Rock N Roller Multi-Media 2-Tier Shelf kit for R8, R10, and R12 carts converts a Rock N Roller cart into a full-featured mobile workstation. The main shelf (61 x 79 cm) provides a spacious working surface for audio and film equipment or other professional gear. The upper shelf supports up to 32 kg and measures 25 x 79 cm for placing additional equipment above the main surface. Together, the shelves support a total load up to 90 kg. The shelves are covered with durable carpet material and fold down for convenient storage and transport.