Handle lock for miniature circuit breakers for 5SY, 5SP, 5TE8, 5SJ4...-.HG.. SENTRON 5ST3 locking device as an additional component for residual current protective devices and miniature circuit breakers.These additional components can be mounted universally. They are easy and convenient to install and connect. Thanks to the standard touch protection, safety during installation is reliably guaranteed.Optimal technology for your safety - only from Siemens.