2 Pcs Magnetic Stirrer Mixer Cross Type Stir Bar Spinbar Stirring Cross Magnetic Stirrer and Gear Type (2, Cross Type+Gear Type)

Tried this stir bar because the small one that came with my stir plate wasn't creating a vortex in a 3L yeast starter in a 4L flask once fermentation was under way. Unfortunately this one wasn't even that good. You have to make sure it is centered in the flask in order to set it, you can't just drop it in and move the flask until it catches the magnet on your stir plate, and it throws at anything over 10% on my stir plate no matter how slowly you increase speed. I tried this with water and kept emptying my flask but couldn't get a satisfactory vortex with just 2L. This is problematic because it is extremely difficult to reset the stir bar and I think it might be quite a pain in a yeast starter where you can't see what you're doing.

The magnetic stirrer works just as well as ones I have purchased on lab supply sites. It also looks and feels the same.Cleans easily. Opening my envelope, I found it in a plastic bag without packaging. Rather disappointing.My opinions are my own and I paid for this product. No discount or any form of compensation was offered.

Do not purchase if you are planning to use with the 24/40 fittings or anything less than 1000m. They simply will not fit or are over kill.Both of these mixed and agitated well. With some "slight modifications" I was able to use them in the 24/40 1000ml flask, but... uh, I wouldn't advise it. I only did so out of necessity. Lol overall I'm still happy with the product and would recommend it.

All stir bars were ok except for the star shaped one that has a square magnet inside of it really sucks !

I purchased the 6 pack primarily for the large 50mm, gear and the cross mixing bar. . . I did a test run in a mason jar and then a 2L flat bottom pyrex beaker, and for the cross I couldn't go much past 20% and the 50mm bar I could not even get it to spin. . . It looks like the cross and large bar are poorly balanced.

They work most of the time. Sometimes they do not spin wright, and flip arround. Wish they worked better, but they do look nice.

Bought for stirring C60 in olive oil (1000 ml). Wanted to try these to compare to standard cylindrical bars. The star shape did not work at all. The cross shape was just okay. Re-mixing with standard bar.

Does not work!