4 Twin Size Mattress Covers/bags 40" x 12" x 86" (2 Sets of 2) for Box Spring & Mattress FOUR Twin Size Mattress Bags-- One for the Box Spring and One for the Mattress Each cover is 40&quot;x12&quot;x86&quot;-- 12&quot; in Height to fit Pillow top mattresses with ease! Made of 2 mil poly material, Water resistant and Tear resistant!