A wall mountable connector may be secured to a wall in order to provide mechanical and electrical connections to a thermostat. In some cases, the wall mountable connector and the thermostat may, in combination, be configured to permit the thermostat to attach to the wall mountable connector only when the thermostat is in a particular orientation relative to the wall mountable connector. In some cases, the wall mountable connector includes a plurality of pin terminals that are configured to accommodate a plurality of pins extending from the thermostat. The interaction between the pins and the pin terminals may provide a lock and key arrangement between the wall mountable connector and the thermostat.