With a heavy-duty a non-allergenic commercial grade vinyl cover that resists mildew and moisture, the DuraLoft Crib Foam Crib Mattresses use supportive foam for durability and comfort. Its special locking-stitch design eliminates the risks associated with fraying. To be used with portable and compact cribs only. Features: -For portable and compact cribs only -2" Mattress compatible with Little Dreamer, HideAway, Travel Sleeper, and StowAway Compact Cribs -3" Mattress compatible with Serenity Com pact Cribs -4" Mattresses compatible with Pinnacle Compact Crib -Sleeping surface: 38" W x 24" 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