Interlocking tube rack holder helps organize and facilitate storage in chest freezers. The Micronic Modular Vertical Freezer Rack holders can be combined together to create a tower of up to 15 holders. One rack holder has a capacity of a single Roborack-96, Comorack-96 or any of the Micronic ULT Racks. When using the Loborack-96 with a low cover / Micronic 96-1 Rack, one rack holder fits two Loboracks, providing a space saving storage solution. Holder can also accomodate most deepwell or multiple well plates. Each pack contains 10 holders.