Lightolier LyteCaster Collection Low-voltage 3-3/4-Inch frame-in kit includes housing and mounting frame. Kit contains junction box, mounting bars and socket housing. This 0.026-Inch galvanized steel housing accommodates MR16 lamp that has 2-Pin socket. This Airseal® housing reduces air leakage to less than 2 CFM at 1.57 PSF. Socket features aluminum housing. Mounting frame has 0.036-Inch galvanized steel construction. Junction box features 0.063-Inch galvanized steel construction. Junction box measures 2-Inch x 4-Inch x 4-Inch. Mounting bars have 0.059-Inch galvanized steel construction. Kit is UL listed.