Siemens Emergency stop pushbutton, red, key-operated releaseProduct Overview EMERGENCY STOP mushroom pushbutton, 22 mm, round, metal, shiny, red, 40 mm, with RONIS lock, lock number SB30, positive latching, acc. to EN ISO 13850, key operated release. Part of the SIRIUS ACT series, this emergency stop pushbutton is engineered for safety systems requiring enhanced security and controlled access. The RONIS lock system with key operated release ensures that only authorized personnel can reset the emergency stop