Friction torque lid stay holds lid open at any position along its range of motion. Friction torque in one-way direction only. Torque strength adjustable Handed: specific left and right hand mounting. Can be used individually or in pairs. Torque Calculation: Torque = Door Height x 1/2 x Door Weight WARNING: This product can expose you to cadmium, lead, nickel, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65WARNINGs.ca.gov.