Recessed track housing system for 2-circuit Contech track. All mounting hardware is provided for installation finishing to dry wall or suspended ceilings. Spacers are supplied with RTH-4 and RTH-8 to adjust for thickness of 2-circuit track. A major feature and benefit of Con-Tech track and track components are the "can't miss" polarity indicators which work together and assure proper polarity. Each section of track has groove incised length-wise into the exposed underside of the track indicating the positive terminal. All connectors and fixtures adapters also have an arrow or "P" pm their connecting ends indicating their positive terminal. Track, connectors, and fixture adapters are designed to fit together easily when polarities are correctly aligned.