Elco Lighting EL918RICA 6" Airtight IC Sloped Remodel Housing 6" Airtight IC Sloped Remodel Housing Ceiling Opening: 6 1/2" x 6 3/4" 7 1/2 height allows for use in 2 x 6 construction,Adjustable housing accommodates up to 1 1/4 ceiling thickness,For use in sloped ceiling with 5/12.