Flat sides provide excellent contact for locknutsExternal ears are used to nail the ring to the wood formTop cover is removable for before-pour workEars on inside of box are for fixturesWaxed fixture ears prevent concrete from interfering with the threadsConcrete rings are used with poured deck (floor) in high-rise constructionThese boxes are installed on wooden or steel concrete formsAfter the forms are removed, the box is flush with the concrete4 in heightDouble row of 1/2 in and 3/4 in side knockoutsConduit wiring system50 lb fixture recommended load