A roll control protector, where the triangles are fixed with Velcro. When you lie on the bed, it is not possible to undo the Velcro belts. The belts are led underneath the mattress. The cover one lies on is a MMC 210 PU of the same quality as the mattress cover. The foam is a CMHR 25. This is a fire-retardant foam having a density of 25 kilograms. 20 x 20 x 90 cm.