Note:suitable for 18mm hole diameter tube, can holds 50pcs tubes(not included). Versatile and functional that can hold test tubes and centrifuge tubes, improving work efficiency. The test tube holder has proper storage capacity, making it easy to organize and classify tubes. The sturdy construction of the test tube rack makes it can be used for long term, not easy to deform or break. The test tube holder can be placed on table or shelf for easy access during experiments. , the test tube stand is easy to take, convenient to store, a good tool for most researches. It's DIY kits, needs to by yourself. Colour:Random Color(The color is random, and the designation is not accepted) Material:Plastic Package Contents: 3 x Centrifuge Tube Rack Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.