Features:Made of polypropylene, durable and light weight, easy to carry.Fit for 13 to 16mm test tubes, round holes, hold 50 tubes.Economical and space-saving rack for applications in lab or at home.3 Layer, 2 slots, each layer has a direction, slide the shelves in from one side, the other side has a lip that stops it, fits very snug.Specifications:Material: Polypropylene (PP)Color: White, Light BlueModel: 50 holeHole Diameter: 16mmFit for: 13-16mm tubesSize: 255mm x 115mm x 65mm / 10" x 4.53" x 2.56"(L*W*H)Package Contents:1 x Tube Rack