All-glass Tenbroeck tissue grinders with precision made interchangeable pestles and tubes. Clearance between pestle and tube .004-.006 in. (0.1-0.15mm). Designed for hand operation, but can be slow-speed motor driven by inserting a rubber stopper and metal rod into pestle. Hollow handle permits packing with ice. Expanded reservoir and pouring lip. For tissues such as liver, intestines, and heart. Wheaton-33 low extractable borosilicate glass.