Say hello to a peaceful night's rest with this Serta twin mattress. This firm, twin-size mattress uses Serta's SertaFlex Inner spring design and steel border reinforcement for optimal support and to avoid sag. Unique foam layer that provides cushioning comfort while maintaining resilience for durable support at the sleep surface. Mattress also features FireBlocker which helps to keep families safe by exceeding federal and state flammability standards. Click here for warranty information.