UWS Secure Lock 48" Under Tonneau Chest Box Model SLC-48-MBUWS Secure Lock 48" Under Tonneau Chest Box Model SLC 48 MB Compatible with most tonneau covers, the UWS Secure Lock under tonneau chest box is perfect for adding functional storage space and organization to your pickup while maintaining the option of keeping your truck bed covered. It features a low profile, dual locking handles, a patented RigidCore foam filled lid and extra thick, non corrosive construction. The UWS under tonneau tool box features