16 PCS PTFE Magnetic Stirring Bar Set - Laboratory Stirrer Mixer Bar - Stir Plate Magnet Bar Rod Stick - Spinning Spin Mixing Bar for Lab (8 Big + 8 Small)

The smaller ones are perfect in 100-150ml beakers. The larger ones for 250-500ml beakers. I have autoclaved the smaller ones many times with no issues other than some discoloration.

I use these for mixing compost teas in a beaker. Usually at 750rpm for 8-12 hours, then 900-1000 rpm for 2-4 hours. With some harder debris in the compost I'm sure when they might chip or worse, but after multiple uses they're standing up to the task. However, getting them perfectly clean after can be very difficult, but for me currently I don't need perfect sterilization.

Seriously it’s a it’s a magnet. I think it would be hard to mess this up. They didn’t mess this up.

Does the job no issues. Simple

I've used a few so far and they're working as expected. I use with agar and am able to microwave my media bottle with the magnet inside without any issues.

Works as they should

haven't used them yet but they look exactly as advertized... interestingly, packaging flimsy but they are magnets so they ended up in a wad in the envelope-mailer they were shipped in.

I like the size variety. Great stirrers!