4 inch low voltage IC Airtight new construction housing with magnetic transformer is suitable for insulated ceiling and damp location. Below ceiling accessible. EC50M 50 VA 120V / 12V magnetic transformer included. For use with MR16 bipin base max 50W 12V halogen lamps (not included). Compatible with following trims: R2000, R2000VSM, R2000VST, R2010VSM, R2010VST, R2020, R2030VSM, R2030VST, R2051, R2100, R2100VSM, R2100VST, R2100VT, R2110VSM, R2110VST, R2120, T2010V, T2000VL, T2010VL, T2000VS, T2010VS, T2000VLS, T2010VLS, R2130VSM, R2130VST, R2450VT, S2000, S2051, S2100, T2000, T2000V. Takes up to 7/8" thick ceiling. Cutout 4.25 inch. Dimensions: 19.5 inch length, 10 inch width, 7.125 inch height. UL listed.