The RotopaX Locking Pack Mount is a keyed twist-lock base that bolts to any flat surface and holds a RotopaX container down tight. It measures 4 in by 1 in by 3.75 in and weighs about 1.6 lb. Set the mount, drop a pack on it, line up the container dimples, and turn until snug. The DLX handle gives you extra leverage so the pack seats hard against the surface and stays quiet on washboard.
The difference between this and the standard pack mount is the lock. Insert the keyed cylinder and the container can't be twisted off, so a fuel can or storage pack stays put at a trailhead or campsite. It deters a grab-and-go theft, not a determined thief with tools, and it fits the standard RotopaX dimple pattern shared across the 1, 1.75, 2, and 3.5-gallon packs.
One trade-off to know up front: the lock works only when the mount is bolted straight to the surface. Pair it with a pack mount extension and the locking function is defeated. Mount it directly to a bed rail, bumper, rack, RTT base plate, or trailer wall and you get both the lock and the lowest, tightest hold.
