Perfect Sleeper X Knox Firm 13.5 in. Twin XL Hybrid Mattress

Featuring 5 support zones designed for full-body spinal alignment with a combination of supportive coils and 1" Perfect Conform™ Memory Foam. Plus a classic quilted feel that makes for night after night of perfect sleep. Memory foam and cooling upgrades available. Serta® Perfect Sleeper X Knox Firm 13. 5 in. Twin XL Hybrid Mattress