Abstract: A cap and cover assembly is for use with a pick up truck having a truck box. The cap and cover assembly includes a top panel and opposing sides. Each side has a flexible side portion hingeably attached to a rigid side portion. The flexible side portion has one side attached to the top panel. The opposing sides are releasably attached to the truck box. The opposing sides have a cap configuration where the sides are in a stowed portion and a cover configuration when the sides are generally upright. In one embodiment the cap and cover assembly also includes a spring loaded lift arm adapted to aid in the cover to cap conversion. In another embodiment the sides are arranged such that in the stowed position the sides create a “keystone” arrangement.