4", New Construction Recessed Housing, Air Tight, For Use With Insulated Ceilings, Pre-Installed Bar Hangars Fit Up To 24" Spacing, T-Bar Clips For Drop Ceilings, 5-1/2"H Fits 2" x 6" Joist Construction, Adjustable Porcelain Socket, Integral Thermal Protector, 7 Junction Box Conduit Knockouts Are Uniform 1/2" Size With True Pryout Slots, 4 Pryouts With Integral Strain Relief For Non-Metallic Sheathed Cable, 3 Push In Wire Connectors For Easier Installation, 4-1/2" Opening, 120V, Compatible With Halo 4" Trims, UL/cUL Listed For Damp Location.