The CL-4000 is designed for production environments where torque repeatability is a must to maintain quality standards. Intended for vertical insertion of fasteners. Also recommended wherever cleanroom assembly or static control is an issue. Each driver comes with a torque spring types which are color-coded, a blue (light) and a red (heavy). - The CL series is electric torque screwdriver that is designed for heavy-duty production and delivers reliability and precision torque. Ensures accuracy in fastening with precision automatic shut-off clutch once preset torque is achieved.