With a heavy-duty a non-allergenic commercial grade vinyl cover that resists mildew and moisture, the DuraLoft Full Size Crib Mattresses use supportive foam for durability and comfort. Its special locking-stitch design eliminates the risks associated with fraying. To be used with full size cribs only. Features: -For full size cribs only -3" Mattress compatible with Travel Sleeper Full Size Crib -4" Mattress compatible with Serenity and Pinnacle Full Size Cribs - 5" Mattresses compatible with Ser enity, Travel Sleeper, and Pinnacle Full Size Cribs -Sleeping surface: 52" W x 28" D -Follow all crib manufacturers` directions to appropriately size a mattress for a specific crib -Meets or exceeds CPSC, ASTM and JPMA crib safety standard