best mattress in thillainagar growell beds and furnitures trichy A spring with foam mattress, also known as a hybrid mattress, combines the support of traditional coil or spring systems with the comfort and contouring properties of foam layers. Here’s a detailed look at the features and benefits of spring with foam mattresses The core of a spring with foam mattress typically consists of a coil or spring system. These coils provide foundational support and help distribute body weight evenly across the mattress. They come in different types, such as Bonnell coils (hourglass-shaped) or pocket coils (individually wrapped).