Mounting Frame : .036 galvanized steel. Accommodates all ceilings up to 1 thick. Four slots are positioned 90ยบ apart to simplify alignment. nsulated ceiling Housing : .018 galvanized steel. CSA certified for direct contact with thermal insulation. Internal thermal cut-out insures against overheating due to incorrect lamping. Rotoclips : Easy reflector trim installation. Push-in / twist-out Rotoclips hold reflector flush to ceiling. Mounting Bars : (4) 18 ga. galvanized steel. 13 long bars extend to 27. rotatable and lockable, integral t-bar tabs. Spike detail eliminates the need of additional nailing. Attaches to wood joist or T-bar without need ofaccessories.