Housing: 0.026 (#20 ga.) galvanized steel. U.L. listed for direct contact with thermal insulation. Access door for inspection of junction box. Mounting Frame: 0.036 (#20 ga.) galvanized steel. Accommodates all ceilings up to 1 thick. ICM version has 3/8 deep integral lip. Four slots are positioned 90° apart to simplify alignment. Push-in/twist-out rotoclips hold reflector flush to ceiling. Junction Box: 2 x 4 x 4, 0.063 (#14 ga.) galvanized steel. U.L. listed for, maximum of 6 No. 12 ga., 90°C through branch circuit conductors. Quick release L shaped cover for outside access to wiring. Access door inside of housing allows easy inspection of wiring without removal of housing. Integral cable clamps permit attachment of nonmetallic Romex® or armored cable without the need for additional connectors. Mounting Bars: 0.059 (#16 ga.) galvanized steel. 13 long bars extend to 27, rotatable and lockable, with integral T-bar tabs. Attach to wood joist or T-bar ceilings without need of accessories. Socket Housing: Impact extruded aluminum or galvanized steel. Socket: Porcelain medium base; nickel plated screw shell. Pre-wired with #18 ga. SF1 leads to junction box. Thermal Protector: Meets NEC and U.L. requirements. Located inside housing.