Features: 1.Very user-friendly design for better using experience. 2.The seal is doing very well and the test tube will not fall out. 3.Test tube rack is the most basic experimental instrument in the dry test tube of chemical laboratory. 4.A total of 40 small holes, double-layer design, very large capacity. 5.Made of stainless steel for longer service life and durability. specification: Very user-friendly design for better using experience. The seal is doing very well and the test tube will not fall out. Test tube rack is the most basic experimental instrument in the dry test tube of chemical laboratory. A total of 40 small holes, double-layer design, very large capacity. Made of stainless steel for longer service life and durability. : Material:Stainless Steel 304 Hole Quantity:40 Hole Size(Optional):15.5mm/0.61in 18.5mm/0.73in Package List: 1*Test Tube Rack