The SIEMENS ENERGY 5ST3801-1 is a locking device designed to enhance the safety and security of your electrical circuits. It is specifically designed for use with residual current miniature circuit breakers with a handle diameter of 70mm. The locking device ensures that the circuit breaker handle remains securely in the desired position, reducing the risk of accidental operation and providing added protection during maintenance or troubleshooting. With its sturdy construction and easy installation, the SIEMENS ENERGY 5ST3801-1 locking device is the perfect solution to keep your electrical circuits safe and reliable.