Side-mount truck boxes install alongside the truck bed rails with a storage compartment that sits inside the truck bed just above the wheel well. Also called low-side or lo-side boxes, they provide a secure, weathertight space for tools and supplies, keeping the floor of the truck bed free for cargo. They have a single lid that lifts upward and remains open to keep both hands free while accessing supplies. The push-button latching system and self-rising lid allow for one-handed operation.