Storage Test Tube Rack Nalgene™ 24 Place 25 to 30 mm Tube Size Clear 4-1/2 X 12-1/2 Inch

When empty, they can be stacked with any other racks of the same length

Holes are keyed with molded-in numbers and letters for easy identification of tubes

Higher specific gravity than water so it stays submerged in a water bath and won't float

Autoclavable (will reduce strength over time)