This Harmony ZB, single contact block uses fast-on terminals.It is compatible with Harmony XB4 and XB5 control and signaling units.This contact block allows fast and easy replacement and configuration of your push buttons and selector switches.It is easily installed and replaced on XB4 and XB5 complete push-button units and selector switches and connects to control circuits with simple fast-on connections.It protects operators from unexpected contact with live circuits thanks to its IP20 protection index.1 million cycle high endurance under 6A load allows less maintenance and damage in your installation.It has clear color scheme for NO and NC contact block types.Its wide range of operating temperatures from -40°C to 70°C allows versatility in usage of product.