UWS PGS-SM48-B ProGrade Black 48" Steel Side Mount Truck Box One-piece heavy duty 14 gauge steel tubes designed to support extra heavy loads, absorb tool drops and prevent leakage Patented fully foamed lid creates a rigid wall between outer steel layers for added strength, rigidity and solid, secure lid closure Quick-pull handle for easier one-hand access and key lock protection Rotary locking system with stainless steel housing for superior strength and security Connecting rod enclosure helps prevent box contents from bending or jamming the locking system