Glass Erlenmeyer Flask Set with Rubber Stoppers - 3 Sizes - 50, 150 and 250ml, Karter Scientific 214U8

The look and feel of the equipment is good. However, only one of the stoppers fits properly in one of the flasks. In the smallest bottle one of the stoppers falls in, another is too big to fit at all, and the third stopper gets snug as it becomes flush with the top of the flask. (very difficult to remove)The two smallest stoppers fall inside the two larger flasks. The middle flask is actually larger mouthed and the largest stopper nearly falls to flush in that flask as well.The largest bottle has the second largest mouth and fits the largest stopper well. Unfortunately this leaves two of the flasks without stoppers. As well as two stoppers that make great floats.Of course your mileage may vary.According to the size chart on Sciencecompany.com this set should have been shipped with sizes 5, 6, and either 6.5 to 7. Not sure of the size for the largest flask. I think either might work for the largest mouthed flask.Quick update: I have been doing a little research about these flasks, Karter Scientific 214U8 and the reference set listed on Amazon without the stoppers Karter Scientific 214U2 indicates the mouths of the flasks as follows: 50ml: approx 17mm, 150ml: approx 22mm, 250ml: approx 25mm. These numbers are not accurate for the set I received. The mouths were instead as follows: 50ml: approx 26mm, 150ml: approx 31mm, 250ml: approx 28mm. If the flasks were sized as described in the Karter Scientific 214U2, I believe the stoppers that shipped with this kit, would, in fact, fit correctly. So I do not know which is wrong but now suspect I was sent the wrong size flasks, or the flasks mouths have been redesigned to be larger, but the stoppers that come with them were never switched to larger sized stoppers. Don't know which, but clearly something is rotten here.

I ordered two sets of these flasks with stoppers, to use for mixing and storing photography chemicals. I expected a high degree of accuracy, as these are sold as lab ware, but what I received fell short. The stoppers sent for the smaller bottles were completely the wrong size in both sets, with the smallest stoppers falling completely into the little flasks. The largest stoppers fit one flask, but not the other (meaning the necks of the flasks aren’t the same size). Fortunately I had already bought an assortment of other stoppers, so I can still use the flasks. I would say that considering the poor quality control with these, you should look elsewhere if accuracy, precision, and quality are important to your work.

Overall I am satisfied with glassware. Aside from very minor imperfections and finding a large chunk of glass in the 250ml (which scared me as I thought the flask had broken during transit... luckily it was from an unknown source), the glass arrived quickly and as described. The #2 rubber stopper on the other hand was less desirable. The larger stoppers fit well but upon dropping the #2 into the top of the 50ml, it sat down unusually low. I gave the stopper a little press downward to check for a seal (and I'm talking very minimal pressure) and instead the stopper just slid down inside the flask. Perhaps the stopper decided to resize itself correctly once inside the flask (lol) as attempts at retrieving it were futile. That said... I'm still giving a rating of 4 stars, as the set, even minus one, is an amazing deal.Edit 10/20: And 5 stars it is. Thank you Amazon for being amazing and making it right. Never dissatisfied with Amazons customer service.

I love them and have many more. The price and quality are superb. I have used them and tested them many times. They hold up perfectly under high heat and temperature changes. Great set of lab grade glassware. Karter Scientific makes and provides high quality glassware that is affordable for the hobbyists like myself. I own lots of their glassware.

I use these for brush cleaning containers for hobby painting (models, miniatures etc...) as they have wide bottoms and are sealable and this makes them much harder to spill. They come with a good stopper, are pretty tough and overall is a good for what I need.

i ordered the flasks with rubber stoppers included and just received my package and the stoppers do not fit the flask??????? there are three and only the big one fits, the small two are way to small to use on either? can i get som that fit??? also the paint on them looks scrapped away as if they are worn already, not sure why they wouldn’t come brand new but anyways wouldn’t recommend

As someone else noted, the stopper for the smallest flask is undersized, so pushing it down even slightly would force it right into the flask. Odd that this hasn't been corrected yet, or that nobody even bothered to check if it fit before selling it.

These are strong, and I don't know what other people are saying about the smaller rubber stopper being to small. Mine is not. And they take quite the solvent abuse as well. For the price, they are fine.