Check the listing for details. Lab Glass Separate Flask with Easy Open Clamp 250mL. Condition: New. Listed at 116.00 USD. This is the Separate flask,it could be easy to open. 1.250mL flask with 100mm big mouth ,easily to clean and put or pick the material from the flask.2.Glass lid,main taper joint is 24/40.3.Easy open clamp,it is the Stainless steel base,Resistant to acid and alkalinity corrosion.4.Any size or joint cusomized would be availible. If you need the customized size,please contact with us by the message before place the order. it is the smooth flange,not the O-ring flange,if you need the O-ring flange,please contact with us before you will place the order. Our flasks are heavy wall design, made by hand-blowing to ensure uniform wall thickness, and made of high-quality borosilicate glass G3.3 and annealed at 800 degree Celsius, can be heated directly in an open flame and can withstand typical laboratory thermal variations in Chemistry processes like heating and cooling. Handle blowing by the glass blowers,not made by the Pouring If the item will be broken in the delivery process,we will send the replacement to you right now. Be Made From G3.3 Borosilicate GlassAnnealing Point ------560CLinear Coefficient of Expansion------ 32×10-7/CSoftening Point------820C