Snap-mount sockets are designed to mount on BNDN-1000 mounting rail. The built-in mounting clip eliminates mounting hardware and reduces mounting time by eighty percent. For spacing between adjoining sockets, use SA-406 DIN rail spacer. Spacers : 0.197" in width. Spacing can be adjusted according to the amount of spacers added. To prevent sideward movement, use BNL-5 end clip at each end of socket row. To Mount: Place socket on mounting rail and press down. To Remove: Pull clip out with screwdriver and lift socket. Get smart with the fully programmable IDEC smartrelay, a compact, expandable CPU that can replace multiple timers, relays and counters.