24-Well Metal Rack for 1.5ml Centrifuge Tubes manufactured by Bioland Scientific, LLC. can accodomate 1.5ml centrifuge tubes and keep them in cold after fully refrigerated or leave on ice. It is used with a silica gel base to ensure a longer cooling time. After being fully refrigerated (-20℃ for 4-6h), the Metal Rack can keep low temperature for 1-2 hours.