








⚡ Stay powered, stay safe — test like a pro every time!
The Martindale CP501 Classic Check Plug is a compact, battery-free 240V UK socket tester that detects 28 common wiring faults using three bright LEDs for clear fault codes. Designed with a tough ABS casing and ergonomic grip, it offers quick, reliable socket verification for both electricians and homeowners.







| Manufacturer | Martindale Electric Co Ltd |
| Part number | CP501 |
| Item Weight | 60 g |
| Product Dimensions | 6.5 x 6.5 x 4.7 cm; 60 g |
| Item model number | CP501 |
| Colour | Blue |
| Style | Classic |
| Material | Abs |
| Power source type | Electric |
| Item Package Quantity | 1 |
| Number of Pieces | 1 |
| Measurement System | Metric |
| Measurement Accuracy | 50kohm |
| Included components | 1 x Martindale Socket Tester |
| Batteries included? | No |
| Batteries Required? | No |
S**.
Handy tool
Handy to have in your tool box.
P**R
Classic, works as you'd expect
Does what it should, reliable & robust.
S**F
Does The Job But...
This will tell you if you have power or various combinations of crossed mains wires etc and works OK but I wish I had bought the version with the buzzer. With an audible warning if there is power to the socket I do not have to keep checking at the consumer unit. Apart from that it is handy, sturdy and small enough to have in your tool bag.
T**Y
Brilliant plug
This is a great item. The previous one from a different company didn’t work
R**N
A Classic Tester which works very well
Martindale testers have been around for decades, are simple to use and reliable. I quickly found out some of my sockets had live and neutral reversed - so much for professional installers!!
A**N
simple to use
This is simple to use ,but once you have checked the outlets in the house that will be the end of its usefulness You will then lend it out to someone else , after the second time it will be lost to you for good .
M**N
No problems to report
No problems to report, arrived quickly,good price,I find it reassuring to carry a quick check on a socket after fitting it
C**E
Does all you need it to.
Perfect for work as an electrician. Always bemuses me though the price for the sake of a buzzer compared to those without. Only reason it’s not 5 stars.
Trustpilot
3 weeks ago
1 week ago