Polypropylene rack has 96 wells for 0.5ml microcentrifuge tubes on one side and 96 wells for 1.5 to 2.0ml microcentrifuge tubes on the other side. ells ae arranged in standard 8 x 12 array. Handy lid snaps into place via tabs on each and of the rack. 0.5ml wells are separated by molded-in grid lines. making them easier to see, and raised rings are around the 1.5 to 2.0ml wells make tubes easier to remove. Autoclavable. Pack of 5.