Mounting Frame: .036 (#20ga.) Galvanized Steel. Accommodates all ceilings up to 1-1/2 thick; including existing or inaccessible areas. Trim Clips: “Push In / Twist Out” Stainless Steel clips hold reflector flush to ceiling. Junction Box: 2 x 4 x 3-1/2 (22cu.in.) .032 (#22ga.) galvanized steel. CSA Certified for maximum of 8 (#12ga.) through branch circuit conductors. UniFrame™ Mounting System – Grid Ceiling: Tool free mounting in grid ceilings. .036 (20ga.) Galvanized Steel interlocking slide bars adjust to 24-1/8 long accommodating 24 O.C. Ceiling Grid. Adjustable speed clamps for positive attachment to grid ceiling systems. UniFrame™ Mounting System – Wood Joist Ceiling: Integral nailing tabs,alignment guides, fastener holes and bendable strapping guides for wood joist installation. Galvanized Steel interlocking slide bars adjust from 12-15/16 to 24-1/8 long to accommo spacing, with or without strapping. Suitable for Steel Ceiling construction using standard 1/2 EMT.