Bila membeli 1pack(10 pcs),akan memakai packaging original Siemens 3RH1921 1-pole auxiliary contact block Siemens 3RH1921-1CA10 1-pole front mounted auxiliary contact block with 1 N.O. contact. Can be combined with up to 3 additional 1-pole contact blocks. An extensive range of 3RH1921-1CA10 auxiliary switch blocks is available for various applications. The contactors themselves do not have an integrated auxiliary conducting path. One 4-pole or up to four single pole auxiliary switch blocks (with screw or Cage Clamp connections) can be snapped onto the front of the contactors. When the contactors are energized, the NC contacts open before the NO contacts close. The terminal designations of the 3RH1921-1CA10 single-pole auxiliary switch block consist of location digits on the basic unit and function digits on the auxiliary switch blocks. In addition, 2-pole auxiliary switch blocks (screw-type terminals) are provided for cable entries from above or below in the style of a four-connectorblock (feeder auxiliary switch). If the available installation depth is restricted, 2-pole auxiliary switch blocks (screw or Cage Clamp connections) can be mounted laterally on the left or right.