made from boro 3.3 glass tubing directly,heavy wall.uniform,high quality and reasonable prices. made from high boro 3.3 glass tubing directly.uniform,with heavy wall.high quality and reasonable prices.Have a good sales market places such as :UK,CANADA AND U.S.A.Please see the following sizes: Socket sizeCone size14/2314/2314/2014/2019/2619/2619/2219/2224/2924/2924/4024/40 Adapter Claisen