--- product_id: 10179695 title: "Extech RE300 ExStik Waterproof ORP Meter, Flat Electrode, 1mV" price: "HK$1998" currency: HKD in_stock: true reviews_count: 11 url: https://www.desertcart.hk/products/10179695-extech-re300-exstik-waterproof-orp-meter-flat-electrode-1mv store_origin: HK region: Hong Kong --- # IP57 waterproof & floats 1mV resolution precision Interchangeable sensor modules Extech RE300 ExStik Waterproof ORP Meter, Flat Electrode, 1mV **Price:** HK$1998 **Availability:** ✅ In Stock ## Summary > 💧 Precision that floats above the rest — never miss a beat in water quality! ## Quick Answers - **What is this?** Extech RE300 ExStik Waterproof ORP Meter, Flat Electrode, 1mV - **How much does it cost?** HK$1998 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hk](https://www.desertcart.hk/products/10179695-extech-re300-exstik-waterproof-orp-meter-flat-electrode-1mv) ## Best For - Customers looking for quality international products ## Why This Product - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Future-proof your toolkit:** Auto-recognizes and swaps probes for pH or chlorine sensors, adapting as your testing needs evolve. - • **Built to brave the elements:** IP57 waterproof design that floats—never worry about drops or wet environments again. - • **Versatile flat surface electrode:** Rugged sensor works on liquids, semi-solids, and solids, eliminating fragile glass bulbs. - • **Lab-grade precision in your hands:** Measures ORP from -999 to 999mV with ±4mV accuracy for flawless water quality insights. - • **Smart memory for seamless tracking:** Stores up to 15 tagged readings with a high-contrast LCD and real-time analog bargraph. ## Overview The Extech RE300 ExStik Waterproof ORP Meter delivers professional-grade oxidation-reduction potential measurements with a rugged flat surface electrode and 1mV resolution. Its IP57 waterproof housing floats if dropped, ensuring durability in harsh environments. Featuring smart memory for 15 readings and interchangeable sensor modules, it’s a versatile, future-ready tool for precise water quality management across industries. ## Description Product Description Take the guesswork out of water quality analysis with the Extech RE300 ExStik ORP Meter. Whether you are managing the chlorination of a commercial swimming pool, monitoring cooling towers, treating wastewater, or balancing a complex aquarium ecosystem, measuring your Oxidation-Reduction Potential (Redox) has never been easier or more reliable. Unlike traditional meters with fragile, easily fouled glass bulb sensors, the RE300 features an innovative flat surface electrode. This unique design allows you to obtain highly accurate measurements in liquids, semi-solids, and even solids, all while minimizing maintenance and preventing damage. It delivers a wide measurement range of -999 to 999mV with a high resolution of 1mV, ensuring you get the clinical precision required for professional compliance and environmental testing. Built for the realities of fieldwork, the RE300 boasts an IP57 waterproof housing that literally floats if dropped in water. The smart interface includes an automatic electronic self-calibration function, a digital LCD with a simulated analog bargraph to visually track trends, and an internal memory capable of storing up to 15 readings for quick recall. As an incredibly versatile platform, the base unit features a built-in chip that automatically recognizes interchangeable pH and chlorine probe modules (sold separately), allowing your device to adapt to your future testing needs. Complete with a protective sensor cap, sample cup, batteries, and a neckstrap, this all-in-one kit is ready to elevate your environmental diagnostics from day one. From the Manufacturer The Extech RE300 ExStik ORP Meter measures the ORP/Redox from -999 to 999mV. It has an automatic electronic self calibration and a simulated analog bargraph which displays the change in ORP readings. It has a high resolution of 1mV and a memory that stores and recalls up to 15 readings and it saves the last calibrated value. The data validation indicators show the user that the reading is stabilized and it features data hold, auto shut-off and low battery indication. This meter is waterproof to IP57 which protects the meter from the wet environment. The Extech RE300 ExStik ORP Meter comes complete with a flat surface ORP electrode, a protective sensor cap, a sample cup with a cap, four 3V CR2032 button batteries and a 48 inch neck strap. Incorporated in 1970, Extech Instruments is based in Waltham, Massachusetts USA, just west of Boston. Recognized for the breadth and depth of its Test & Measurement offering and strong distribution network, Extech was acquired by FLIR Systems in November 2007. Extech Instruments’ high-value, handheld test instruments and FLIR-branded infrared thermal imager are sold through a network of national catalog houses, regional stocking distributors, internet, and international master distributors. The company has become one of the largest manufacturers and suppliers of test equipment and portable printers and the Extech Instruments brand is regarded in many industries as the brand of choice. ISO 9001:2000 certified by TUV, Extech’s enviable reputation is built on innovative products that offer unique and patented designs with features, functions and reliability at an affordable price. Review: Buena compra - Eficiente, práctico y confiable. Review: Worth it - Accuracy and value for money ## Features - FLAT SURFACE ELECTRODE: Say goodbye to easily broken glass bulbs. The rugged flat surface sensor allows for quick, on-the-spot ORP and Redox measurements in liquids, semi-solids, and even solids, ensuring reliable contact and superior accuracy. - HIGH-RESOLUTION ACCURACY: Stop guessing with your water quality. This highly precise digital meter measures from -999 to 999mV with a sharp 1mV resolution and an impressive ±4mV accuracy, giving you laboratory-grade results right in the field. - FULLY WATERPROOF DESIGN: Never panic about dropping your tool in the pool or tank. Boasting a rugged IP57 waterproof rating, this resilient meter actually floats in water, protecting your investment from accidental submersion and wet environments. - SMART MEMORY AND DISPLAY: Keep track of your data effortlessly. The built-in memory stores and recalls up to 15 tagged readings, while the high-contrast LCD features a simulated analog bargraph to help you visualize ORP changes in real-time. - INTERCHANGEABLE SENSOR MODULES: Future-proof your testing toolkit. The smart built-in chip automatically recognizes different probes, allowing you to easily swap the ORP module for pH or chlorine sensors (sold separately) as your needs grow. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B000S8UIVA | | Batteries | 4 Lithium Metal batteries required. (included) | | Batteries Included? | Yes | | Batteries Required? | Yes | | Battery Cell Type | NiMH | | Best Sellers Rank | #123,179 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #9 in Dissolved Oxygen Meters & Accessories | | Color | Blue/Grey | | Customer Reviews | 4.1 4.1 out of 5 stars (32) | | Date First Available | June 20, 2007 | | Description Pile | 4 × CR2032 (3V) batteries | | Included Components | Meter, Batt, Case | | Is Discontinued By Manufacturer | No | | Item Package Quantity | 1 | | Item Weight | 4.2 ounces | | Item model number | RE300 | | Manufacturer | Extech | | Measurement Accuracy | +/-0.5% | | Mounting Type | Surface Mount | | Number Of Pieces | 1 | | Part Number | RE300 | | Power Source | Battery Powered | | Product Dimensions | 0.75 x 0.75 x 200.1 inches | | Style | RE300 | | Voltage | 3 Volts | | Warranty Description | 2 years | ## Product Details - **Brand:** Extech Instruments - **Item Weight:** 0.12 Kilograms - **Battery Description:** 4 × CR2032 (3V) batteries - **Mounting Type:** Surface Mount - **Voltage:** 3 Volts ## Images ![Extech RE300 ExStik Waterproof ORP Meter, Flat Electrode, 1mV - Image 1](https://m.media-amazon.com/images/I/41E6wRYvaLL.jpg) ![Extech RE300 ExStik Waterproof ORP Meter, Flat Electrode, 1mV - Image 2](https://m.media-amazon.com/images/I/51zrltMmIDL.jpg) ![Extech RE300 ExStik Waterproof ORP Meter, Flat Electrode, 1mV - Image 3](https://m.media-amazon.com/images/I/41Uwz5-ml0L.jpg) ## Questions & Answers **Q: Good morning, i would like to know how many probes are included in the instrument? in the second image i see two probes, could i send a real-time imag** A: Thank you for your question. The full set includes: Complete with 6 x AA batteries, SD card, hard carrying case, sample buffers, mini pH electrode (60120B), and Thermistor temperature probe (850188) **Q: Can this perform orp readings without orp electrode? or do we have to buy 67500b standard orp electrode additionally? if so can you offer that as well** A: Yes, you would need to order the orp probe to measure the orp. **Q: Is this unit capable of continuous immersion logging of typical drinking water to SD card? We'll calibrate every 24 hours, but weekly is better** A: Thank you so much for your interest in our products. Yes, the SDL100 is capable to datalog information from 1 second to almost 9 hours. All this data will be saved on the SD card. Please notice that the SD card capacity is up to 16GB. Please check all the specifications of this unit here http://www.extech.com/products/resources/SDL100_UM-en.pdf **Q: What is the settling time for the ORP meter in weak redox solution such as tap water?** A: It's bad ## Customer Reviews ### ⭐⭐⭐⭐⭐ Buena compra *by N***E on October 12, 2025* Eficiente, práctico y confiable. ### ⭐⭐⭐⭐⭐ Worth it *by S***U on December 12, 2024* Accuracy and value for money ### ⭐⭐ Unreliable *by C***B on May 3, 2022* They need to add more In depth instructions. My meter is reading all over the place. I’ll add hupochlorousacid and it goes down. Started displaying ph for some reason. Gremlins. Trying to problem solve or get refund. ## Frequently Bought Together - EXTECH Instruments RE300 ExStik ORP Meter - Apera Instruments AI1113 pH Calibration Buffer Solution Kit (7.00, 4.00), 8 oz. Each - Extech DO600 Waterproof ExStik II Dissolved Oxygen Meter --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hk/products/10179695-extech-re300-exstik-waterproof-orp-meter-flat-electrode-1mv](https://www.desertcart.hk/products/10179695-extech-re300-exstik-waterproof-orp-meter-flat-electrode-1mv) --- *Product available on Desertcart Hong Kong* *Store origin: HK* *Last updated: 2026-09-08*