16 x 150 mm, Clear Plastic Test Tubes with Blue Caps, Pack of 100, KeL Scientific KS-204-BC100 Test tubes are manufactured from premium grade polystyrene. Polystyrene has glass-like clarity. Manufactured fromFDA food grade safe plastic Certified RNase and DNase free test tubes Hollow top caps are manufactured from low density polyethylene (LDPE) Test tube length: 150 mm (5 15/16in) Test tube outside diameter (OD): 16 mm (5/8in) Test tube inside diameter (ID): 14mm (9/16in) Test tube volume: 25ml (.85 oz) Cap length: 18 mm (a little less tthan 3/4 in) Cap inside diameter (ID): 14mm (9/16in) Cap outside diamter (OD): 16 mm (5/8 in) Neither the test tube or cap are autoclavable Test tube max temperature use: 158 F (70 C) Cap max temperature use: 176 F (80 C)