For use with the LiftMaster 8500 Garage Door Opener, the LiftMaster 41A6408 Travel Module is available at North Shore Commercial Door. This part will also work with models 3800P and 3800PLD. The Absolute Encoder III assembly comprises the 41A6408 Travel Module, which will ship the next business day following your order to NSCD. This is Chamberlain part No. 114A3472.