BCA7 Wooden test tube rack-- multi-tier design permits convenient insertion and removal of tubes, and can hold more tubes. Plastic test-tube holder-- perfect for use in many from laboratory testing to food and beverage service. Tube holder-- suitable for holding test tubes whose max diameter is 15mm or under. Lab test tube rack-- detachable, easy to disassemble and install, convenient to carry. 20-hole test tube holder-- can be stored put together or taken apart and laid flat, won't take up much more space.