StonyLab Glass 250ml Short Neck Round Bottom Flask, Borosilicate Glass Single Neck Heavy Wall Flask RBF with 24/40 Standard Taper Outer Joint - 250ml

bought for backup in lab in case one gets broke. have not used yet, but looks good.

It was a good flask, worked well.

Excellent product

Product arrived on time and was well packaged. Glass joint is good and fits up and seals well. glass has a few blemishes but has performed well so far.

Dont get me wrong, I love that when stonylab makes a 1 litre flask it actually holds a litre. But IT WILL NOT FIT IN A STANDARD MANTLE. It's a great quality flask, and stonylab is the closest thing to pyrex quality at that price. Just be aware that their flasks are always a bit larger.

Defective glass upon arrival. Scratches and chips. They said it's normal and fine to use. I always thought you shouldn't use defective glass under vacuum though.

Works as expected. No cracks or breaks.

This flask is just lovely. A full liter is very convenient, and the walls are so heavy that I have no worry about breakage even at that size. One thing I will say is that you need to make sure your glassware is good and clamped in multiple locations in order to handle the weight and to spread it around so you don't get a lot of force on any one joint. Also, these are extraordinarily smooth on the inside and if used as a heating flask will very much require the use of bump chips.