StonyLab Filter Adapter Cones, Premium and Durable Tapered Collar Rubber Stopper Buchner Funnel Flask Cones Adapter Set, Wear-Resisting Smooth Surface, 9 Counts, White

But I feel compelled to write one now so you don't waste your time and money on this product: the instructions appear to be glued to the tops of the cones, requiring you to cut a path through the paper into each adapter cone with a small screwdriver or similar tool in order to "try" to separate them. As you pry the cones apart, you notice how cheap they are because they start to fall apart as you pry them apart; not only are the instructions glued to the top, but the cones themselves appear to be glued together. I just spent about 15 minutes trying to find the one size that will seal a buchner funnel inserted into a flask. I failed miserably at this, and I've come here to warn you against making a purchase. You won't be able to use this product because I need to seal the funnel and flask together in order to pull a vacuum. I won't be able to do this with this product, so I'll need to start looking for something else.

Roberto Jimenez

| Jul 16, 2021

We bought these filter stoppers three months ago and put them to use for the first time today, only to discover that they had melted. They resemble plumber's putty in consistency and leave a residue on hands and glassware.

Kinslee Camacho

| Jan 03, 2022

This, I believe, is due to the fact that the product they originally purchased has run out. Two other people said they got latex paint-scented "cones" and soft, pliable rubber "cones" in their packages. br>br>It's not even worth driving 20 miles one way to return something. Please contact me, StonyLab, so that I can rectify the situation. I adore you all.

Evangeline Rosales

| Nov 16, 2021

They did a good job of sealing my Büchner funnel to my filter flask, but they didn't last long and turned gummy like chewed gum or something; however, I used them with HCl and H2O2, so the chlorine gas could have been the culprit. So, if you're going to use them with similar chemicals, there are better options.

Liberty Hinton

| Feb 27, 2021

The melted mess is sticky and gooey. Either liquid got inside the package these came in, they weren't allowed to cure properly during manufacturing, or they weren't manufactured properly to begin with. Completely ineffective; I literally paid $16 just to open the package and toss them in the trash. What a swindle, to say the least. I strongly advise you to use a different company for these because Stonylab's offering is complete garbage.

Baker CONNOR

| Jul 09, 2021

I, too, did not receive a 'vulcanized rubber' product, as others have. It's time to have some fun. The smell and feel of dough are identical. Aside from that, the cones were not as well-cut as one might have hoped. Overall, the variety of sizes is appreciated, but the largest three are too big for even my 2L flasks, which I believe is due to the tacky-ness of the material. I'll return after more tests because of the material's usefulness.

Anderson Pham

| Apr 17, 2021

Strong acids such as nitric acid, hydrochloric acid, and concentrated sulfuric acid are used in my work. These were required to connect my various Buckner Funnels to my various Vacuum Flasks. br>These are starting to peel and leave chunks on my Flasks, indicating that they are not holding up well to the acids. br>When I unpacked them, they felt sticky, almost as if the rubber hadn't been properly cured. br>They started out white, and you can see how they've changed after three weeks and are becoming brittle.

Damir Lam

| Sep 04, 2021

A gooey mess. The cones arrived stuck together and covered in a strange sticky goo. I was only able to serenade the first two cones before the rest began to break apart. Never had a chance to use it, and the quality was terrible.

Ainsley Turner

| Apr 01, 2021