This polypropylene rack holds 50 ml and 15 ml conical tubes, and a variety of 1.6/2 ml and 0.6 ml tubes. One rack can attach to another by pressing the 1.6 ml and 0.6 ml sides together. The two racks now have twelve 15 ml wells and four 50 ml wells on the same side. Temperature range: -80 to 121°C. Autoclave safe.