Features Made of high quality rubber material, corrosion resistant, safe and durable. Easy and convenient to use, help pipettes extract liquid rubber balls. The suction ball has 3 openings that are used by the force of the elastic band to help suck the solution into the pipette. Be careful not to attract the solution to the ball. In the opening of each ball there is a small safe ball in the rubber tube, provided that the side of the ball can be pressed between the ball and the rubber tube to form gaps between the air and the outside. Feature: 1. The absorption of the liquid can be controlled by the existence or absence of this intermediate space. Specification: Condition: 100% Brand New Item Type: Quantitative Suction Bulb Material: Rubber Colour: Red Opening diameter: approx. 11.2 mm / 0.44 inches. Hole diameter: approx. 5.7mm/0.22 inch E Opening diameter: approx. 12.8mm/0.50inch Hole diameter: approx. 7.6 mm/0.30 inches S Opening diameter: approx. 14.4 mm/0.57 inches Hole diameter: approx. 7.1 mm Weight: approx. 46g/1.6oz Package List: 1 x Quantitative Suction Bulb Package List 1 x Quantitative Suction Bulb