Stainless Steel Wire Wireframe Test Tube Rack, 40 Tubes 15mm Stainless steel test tube rack Size: 8.25"x4.5"x4.5" (21x8.5x8.5 cm) Holds 40 tubes in 4 rows Hole dimension: 16x16 mm (0.6"), fit test tubes with diameter of 15 mm or less