Simmons Kids Series 300 Baby Mattress features 104 interlocking coils with a reinforced border to provide excellent all-round support and durability in a baby bed.More Features and Benefits:• 104 interlocking coils provide long lasting support for better sleep.• Hypoallergenic 100% vinyl cover for healthy clean protection• Our Patented No-Flip single-side design requires no flipping turning or rotating for the lifetime of the mattress for your convenience.• Square corner design for safe fit in standard cribs Reinforced borders resist tears and rips• Built tough to last through the toddler years (Stage Two)• Limited 25-year warrantySize:• 27¼" wide• 51¾" long (+/- ¼")• 6" tall