The Alpha Communications®/Tektone OR601 series outdoor remotes are designed to fully surface mount on the finished wall surface. They can also be mounted over a single gang flush electrical 'gem' box. No back box is required for surface wall mounting. The model OR601 is finished in a Walnut woodgrain and black finish. The model OR601W is finished in an All-White plastic finish. The OR601 remotes are 2-wire type and are normally used with systems such as the PK543, IR704B/PK724, 'EK' series music-intercoms, and the SM103B/BD Tek-Trio masters. They can be used on the SM201B, SM203B, SM205 series, SM210 series, or SM400 series masters, with the addition of a model EC105 non-polarized capacitor.