The Potter-Elvehjem tissue homogenizer has a ground glass pestle and tube. They are suitable for processing tougher tissues such as connective tissue. Clearance between the pestle and tube is .004-.006. The Potter-Elvehjem ptfe pestle is suitable for softer tissue such as the brain or liver. Working capacity: .5ml Shaft od x pestle oal (mm): 3 x 130 Reservoir od x tube oal (mm): 12 x 80