Type B1 non-contact devices (such as photo-beams) and/or Type B2 contact sensors (such as reversing edges) are required for most automatic gate system applications. DKS gate operators require a minimum of one (1) device to be connected in each direction of travel - otherwise the operator will not run. All entrapment devices used with DKS gate operators are monitored per the requirments of the UL 325 Standard for Safety. Includes mounting channel - ideal for barrier arms 2-Wire Contact Edge: NO or 10K Termination