These heavy-duty, polypropylene racks link together to meet custom rack needs. They feature an interlocking system of tabs and slots for easy connection and sturdy fit. Each rack has four sides that hold either four 50mL conical tubes, twelve 15mL conical tubes, thirty-two 1.5mL microtubes, or thirty-two 0.5mL microtubes. Autoclavable. Dimensions: 17.5Wx9.5Dx5.1Hcm (67/8x33/4x2").