5ml polystyrene round bottom culture tube 12 x 75mm with 2 position screw cap sterile 500 cs

Crystal clear polystyrene round bottom culture tubes with a unique two-position screw cap for growing aerobic and anaerobic cultures. The specially designed cap has two stop positions. Rotate a 1/4 turn and listen for a positive click. The cap is now partially open. Rotate another 1/2 turn to click it again and completely seal in the tube contents. The top of each culture tube cap is flat for easy marking Easy to read graduation lines. 20 bags of 25 tubes.