DescriptionMade of plastic material, 50 holes, double layers, each socket is 15mm diameter. Crystal clear polystyrene tubes supplied with high grip stoppers. Reusable and hand washable.Perfect for laboratory, provide clear view of the tube contents and convenient insertion and removal of tubes.Features- Color: As shown. - Material: Plastic. - Size: 25.5 x 11.2 x 6.7 cm. - Made of plastic , lightweight, convenient to carry. - Detachable, convenient to store. - Easy to install. - Three tier test tube rack holds 50 tubes. - Suitable for 15mm wide test tube.