Expanded PVC foam disks are chemical resistant and withstand temperature from -196 to 93°C. Pre-bored holes maintain a firm grip on your sample tubes while still allowing for easy insertion and removal. Racks are available in five colors with 30 large (17mm) holes for 15mL conical or 13mL Falcon tubes or 44 small (10mm) for1.5mL microcentrifuge tubes. Disks measure 21cm in diameter and 1cm thick. Blank disks (in two thicknesses) are available so you can bore your own holes in the exact size and location you need.