Checkline R55 [MR55-5000] Square Drive Torque Sensor, 3/4" Drive Size, 5000 lbFin Capacity. This rugged series of torque sensors is ideal for a wide range of torque testing applications in numerous industries. Square drives on both ends permit inline use with a torque wrench, or for use in OEM and other applications. Ranges available up to 5,000 lbFin (550 Nm).