This budget mattress has been designed and constructed with a European-engineered Bonnell open coil spring unit, allowing the weight to be distributed evenly across the mattress for extra comfort and support. These mattresses are ideal for bunk beds, cabin beds, triple sleepers, etc but are suitable for all base types. This is a quality children's mattress containing 5 layers of comfort fillings over a 13.5 gauge open coil spring unit and covered in hardwearing check fabric. The mattress has been designed to be specifically dual-sided and we advise you to rotate or turn over your mattress regularly for the best results and to keep your mattress in pristine condition so you can enjoy long-lasting comfort. With our new innovative in-house technology, the mattress will be vacuum-packed. We recommend that you do not leave the mattress rolled and boxed for more than 7 days after receipt. Vacuum-packed mattresses do not have side supports, therefore prolonged sitting on the edge of the mattress is not recommended.