4 Inch Twin XL Box Spring Heavy Duty Metal Mattress Foundation Bed Base with Fabric Cover, Easy Assembly Twin XL box spring with metal slats compatible with any memory foam or hybrid mattress. Noise free construction design twin XL metal box spring provide you a comfortable sleep time. Easy to assemble metal twin XL box springs, include hardware, tool and clear instructions. Come with fabric box spring cover that can be removed for spot cleaning. Heavy-duty and stable metal box springs can support up to 1500 LBS. Box spring twin XL size dimensions: 79.6" L x 37.6"W x 4" H for mattress size: 80"L x 38" W.