Use this unit to generate diazomethane and other gases for gas chromatography, mass spectroscopy, and NMR studies. It features Clear-Seal grease-free joints that have never been ground, and doesn't require an O-ring. This generator comes complete with a plastic standard taper joint clamp, a 13-425 screw cap with cut-out top, and a PTFE faced rubber liner. It's made with Wheaton 33 low extractable borosilicate glass (meets ASTM Type I Class A and USP Type I standards). Note: Please use a safety shield and efficient fume hood when generating diazomethane or similar gases.