Serta - Serta Tranquility Crib Mattress - ECO Firm A firm, eco-friendly sleeping surface is provided by organic cotton layers, and ensures restful sleep for your little bundle of joy. The Serta Tranquility Eco- Firm crib mattress features firm, balanced support throughout with heavy gauge coils, corner supports, flex clips and full perimeter border wire. It features an easy-to-clean, laminated cover. Cover adorned with an adorable Serta sheep pattern. 52.5L"x27.3W"x5.8D" Features include: -Top inside layer is Serta Fireblocker, providing gentle sleeping and safety using exclusive material. Cotton blend top layer ensures extra comfort.-Dual Sided - Stage 1 for baby s slumber and Stage 2 for an active toddler-Stage 1 Infant Side provides a safe, eco-friendly sleeping environment through a layer of ortho-insulator and a layer of organic cotton-Stage 2 Toddler Side provides a safe, eco-friendly sleeping environment through two layers of organic cotton.-Flex mesh support prevents the loss of cushioning.-Additional support provided by organic cotton layers for a safe, eco-friendly sleeping surface. -8 Mattress vents to keep sleeping environment fresh with natural air circulation.-Balanced support from full perimeter border wire for firm edges when baby is standing. -4 side flex clips and 4 corner supports for added firmness. -Security of edges assured by heavy duty cloth binding with lock stitching. This is stronger than vinyl. Lock stitching prevents the entire binding from unraveling if any threads become loose.-Meets all Federal and State safety standards.-Mattress also fits toddler bed frames.-Made in the USA.-Lifetime warranty