Logic Board for the MM371/372/571/572 Operators Microprocessor-based control board is set for single or dual leaf, pull-to-open or push-to-open installations. Control board has temperature compensated circuits. Learn based digital transmitter technology provides millions of codes for enhanced security. Receiver is tuned to 318 MHz. Opener length with push-pull tube fully retracted is 37 1/4", mounting point to mounting point. Maximum stroke is 17". Adjustable auto-close timer (OFF to 3–120 seconds) Power terminal block accommodates a transformer or solar panels. Accessory terminal block fully compatible with all Mighty Mule access controls. Control board allows connection of edge sensors and photoelectric sensors. Audio entrapment alarm sounds if unit encounters an obstruction twice while opening or closing