The small, approx. 1 1/2" x 1" rectangular relay is for the high beam flash when you pull back on the indicator lever. It gives out a useful clunk as it snaps in and out. The later multi terminal relay 2 1/4" x 1 1/4" relayused in the 140 and 240 isn't normally used on the 120 but can be adapted for some uses, if needed. For whatever reason USA regs wouldn't allow flashing of the headlights. but this useful ability could easily be made to work with minor changes to the wiring plus the small relay.