Contact Block Holders and Contact Blocks This range of modular contact blocks from ABB feature self-cleaning contacts. This is capable by using a built-in wiping mechanism. When operated the moving contact rolls over the fixed contact and slides sideways. This feature ensures a good, clean contact even in applications of frequent or infrequent use. The contact blocks also feature easy snap in connection to the contact block holder which in turn provides an easy snap in connection to the operator head. This feature also provides reduced maintenance time when removing the contact block holder from the operator head as there is no need for additional tools. This range of modular contact blocks from ABB feature self-cleaning contacts. This is capable by using a built-in wiping mechanism. When operated the moving contact rolls over the fixed contact and slides sideways. This feature ensures a good, clean contact even in applications of frequent or infrequent use. The contact blocks also feature easy snap in connection to the contact block holder which in turn provides an easy snap in connection to the operator head. This feature also provides reduced maintenance time when removing the contact block holder from the operator head as there is no need for additional tools.