These Floating Tube Racks from Heathrow Scientific are made of economical polyfoam with carrying handles for easily lifting samples out of baths. Racks are available in four shapes and colors. The green diamond-shaped rack holds four 50 mL tubes, the blue parallelogram-shaped rack holds eight 15 mL tubes, the yellow rectangular rack holds twenty-four 1.5-2.0 mL microcentrifuge tubes, and the blue circle-shaped rack features unique "X" slits to accommodate 0.2, 0.5, and 1.5-2.0mL tubes.