This tube rack for 0.6 and 1.5 mL microfuge tubes allows you to have a rack of assorted centrifuge counterbalances to make balancing your centrifuge fast and easy. There are rack spaces for 0.1 mL increments for both 0.6 and 1.5 mL microfuge tubes as well as 2 additional slots for “empty” tubes. Having 2 empty 1.5 mL tubes will allow you to spin down random things like fluorescent dyes or antibodies in the supplier's vial.