Contact Blocks Siemens contact blocks available in plastic or metal. Easy to use and faultless connection, even when contact blocks are stacked together. Self-holding function of the actuator when mounting Twist prevention integrated into patented holder design Stackable contact modules Suitable for use in extreme environments No special tools required Simple geometry for mounting holes Siemens Sirius Act Range The SIRIUS ACT range of push buttons and signalling devices presents an expertly designed selection of push buttons, pilot lights and switches that are intelligent, reliable and physically robust. An innovative snap-on concept makes the task of installing a unit so effortless that it can be done with one hand. Made with real metals and high-grade plastics, installed with smart functions and interaction abilities, these state-of-the-art push buttons, indicator lights and switches have been extreme element tested to guarantee a long usage life and reliability for all your operations. One-handed installation without special tools Components can be snapped on without having to hold the other side Installation possible in a slanted position Modular concept Stylish design & high-quality materials Extremely Rugged & Reliable Flexible Communication - AS-I, IO Link and Profinet