The Twinkle Galaxy 4-inch Mini Crib Mattress by Delta Children is designed to provide the same comfort and support as a full-size crib mattress. Featuring a hypoallergenic fiber core made from upcycled plastic bottles, it delivers firm comfort that's safe for your baby. Its lightweight design makes it easy to change the sheets, maneuver or flip while its waterproof, vinyl cover blocks wetness to help prevent odor. Vinyl cover easily wipes clean with warm water and mild soap. Fits most mini and portable cribs (not designed for standard cribs or pack 'n plays). Pattern on mattress cover may vary. All Delta Children crib mattresses are GREENGUARD Gold Certified and meet the strictest standards offered by the GREENGUARD environmental Institute, which recognizes products with low chemical emissions, contributing to improved indoor air quality.