Scienceware F18745-0010 Switch-Grid Test Tube Rack, Holds 10-13mm Tubes, Orange. from Cole-Parmer

Each rack comes complete with a set of grids in the size of your choice: five color-coded grid inserts fit 10 to 30 mm dia test tubes. The three tiered design holds each tube securely in place while rubber feet keep the rack from sliding on the benchtop and secure stacking while in storage. Constructed of chemical-resistant polyoxymethylene plastic, the frame and grids are easily cleaned with mild detergent, ethanol or isopropyl alcohol. Autoclavable at 250°F (121°C). 25 possible tube size combinations with one rack! Innovative split-frame design holds up to two different-sized tubes in the same rack. Interchangeable grid inserts let you quickly and easily change tube sizes. Less expensive than purchasing multiple racks