The CryoCup Grinder II is a fantastic improvement on the original grinder The CryoCup Grinder II features an indestructible solid stainless steel mortar surrounded by a grippy silicone insulating sleeve The CryoCup Grinder II is built for years of tough milling The CryoCup Grinder II provides superior results compared to conventional ceramic mortar-pestles and even the original Cryo-Cup Grinder Once cooled the CryoCup Grinder II will increase just 5 degrees in 30 minutes That is 7 times greater temperature retention than the original This phenomenal temperature retention allows for longer milling times needed for tougher tissues Simple to use just cool the CryoCup Grinder II in the freezer for several hours Then remove and add liquid nitrogen to the mortar until the liquid nitrogen no longer evaporates or you reach your appropriate grinding temperature Next add your hard frozen sample to the mortar and mill with the pestle until the sample is sufficiently ground