This clear polypropylene cover for 64-well micro tube racks easily snaps on to keep it firmly in place during transportation and storage. A recessed area in the top of the cover allows for secure stacking of racks one on top of each other. The snap on cover is designed to accomodate the extra height of screw cap microcentrifuge tubes. Material: Polypropylene. Feature: Snap On. Number Of Wells: 64. Color: Clear Natural. Bio Plas® #: 0050.