1Foam Material: These test tube racks are made of high density polyethylene foam, soft yet robust. The closed cell foam is water resistant, washable, and reusable without damaging the test tubes. 2Vibrant Color Design: Brightly colored high density polyethylene foam racks are perfect for holding tubes in water baths, beakers, or flasks, ensuring easy visibility and retrieval. 3Ideal for Educational and Professional Use: These foam test tube racks are extremely suitable for laboratory experiments in schools or professional laboratory settings, providing a secure and stable platform for a variety of test tubes. 4Easy Carrying: This foam tube holder set is compact and being light in weight that can be easily carried for convenient use, ideal for home and on the go uses. 520PCS: This set includes 20 foam tube holders, providing ample storage and organization for your laboratory needs. With each holder designed for long term use, you can rely on this comprehensive set for all your experiments and projects. 20 x Tube Rack