This simple yet sturdy Test Tube Rack can accommodate up to 6 test tubes with a 22mm outer diameter. It is made of sanded, unfinished oak, making it a great choice for limited budgets and is ideal for use in laboratories, science classrooms. It is also handy for households kitchens for holding spices or utensils, and for arts and crafts for holding pens, pencils, and brushes. Overall size: 8"W, 3.8"H 1.75"D.