single mattress store trichy growell beds and furnitures An HR foam single size mattress refers to a mattress made from High Resilience (HR) foam and designed to fit a single size bed frame HR foam is a type of polyurethane foam known for its durability, responsiveness, and supportive properties. It offers excellent support to the body, promoting proper spinal alignment and reducing pressure points. HR foam quickly returns to its original shape after compression, ensuring long-lasting support and preventing sagging.