VWR Modular Heating Block for Tube Combinations Heating blocks accommodate samples. Single block size.9.5L x 7.6W x 5.1Hcm (3-3/4 x 3 x 2in). Centrifuge Tube Combination 1.5 15 & 50 mL tubes. Respecitively: well diameter 11.1 17.1 29. # of wells 43 2. wel