Screw clamp offers on/off and fine control so accurate that it replaces stopcocks in many applications. It can be installed without disconnecting tubing or interrupting operation. It is molded of Delrin plastic and is autoclavable at 121C (250F). It is resistant to acids, alkalis and organic solvents. Clamp accepts flexible tubing up to 14mm (1/2") O.D. Sold in a package of 3.