The round bottom plastic test tube is made of impact resistant PP material, with a capacity of 15 mL and a total length of 12 cm. The bottom arc has no dead corners, making it easy for the magnetic stirrer to rotate and collect particles. Transparent scale with 0.5 mL division, can be boiled in water to 121 ℃, resistant to weak acid and alkali. Equipped with leak proof screw caps and droppers, students can safely conduct experiments such as dissolved oxygen, enzyme reactions, and micro titration without breaking when dropped, suitable for primary school science to junior high school chemistry classes.