LABALPHA 6Pcs PTFE Magnetic Stirrer Mixer Stir Bar, Magnetic Stir Bar, Olive Shape, 10mm/0.39 inch Length

The shape seems to facilitate a more quiet spinning.

These do what a stir bar is supposed to do. No surprises. The magnets are very strong. I've used plenty of stir bars in my career, and these are probably some of the strongest I've used. Since these are rounded on the top and bottom, and pretty slick, I could actually spin the magnet and they'd always stop and orient themselves to the north! Most other stir bars I've used will just sit on the counter, so these were pretty fun, as well as usable! We use this size to stir just under a liter of water constantly. Nice vortex at a low rpm on the stir plate. The only problem that we've had (with all stir bars) is that the PFTE coating will "shred" and leave little flakes in the water. I think it's because of a small ridge on the bottom of my container that is rubbing the stir bar. So, now I need to find a flat-bottomed glass container!

These magnetic stirrers are so you can put them in a laboratory magnetic mixer and create vortexes in your lab solutions that mix the solution components really well. But it doesn't seem like the people who created the product video for this item understand that at all. In the product video, it shows them putting one of these into a beaker and then proceeding to mix the solution by hand with a ruler or something. That's so silly and incredibly stupid, I don't know what to say. Whoever made this product description video clearly does not understand what these are actually used for.

Coating on spinner fell apart after first use. Only exposed to iso and temp only reached 300C.

This product includes 5 olive shaped stir bars with the dimensions of 1.19" x 0.398" with a weight of 0.3 oz each. The PTFE coating is very smooth and stain resistant. These are great for making vortexes when mixing liquids. Very good quality product.

Works on the smaller beaker sizes, though don't try to use a plural amount per beaker because one or more will likely split away from the center.

I work in a lab and have used many different stir bars. I have a cheaper stirrer at home and I tested these out. I used 2 out of the 6 and one was a little more wobbly than the other (which made for the weird wavy vortex) but I cranked the speed up on both far higher than I would typically need for anything and they didn't spin out like many cheaper stirrers do. That coupled with the fact that these cost maybe 1/4 the cost of major lab suppliers definitely makes them worth while. For the photos I just had water in a regular drinking cup and poured some salt in as if I was making a buffer.

Worked great at first... Set at a very low spinning speed, it created a VERY nice agitation/vortex. But When my heating mantle hit 180-200c noticed next to no agitation. Normally I can pull a stir bar out with and extending magnet, but had to stop every, and empty my boiling flask! Was very surprised after recovering the stir bar, that it wouldn't stick to anything, not even to another magnet! I'd rate these bars with a 0 star if possible! I'll be requesting a refund... BUYER BEWARE!