Nalgene™ full-size Unwire test tube racks securely hold a full load of test tubes or centrifuge tubes in the following popular sizes: 13, 16, 20, 25 and 30mm. Up to 72 of the smaller diameter tubes can be held at once. Molded in six bright, permanent colors. ResMer™ manufacturing technology makes these racks keep their bright colors longer. Useful in a wide temperature range with good chemical resistance. Autoclavable.