The AV Stumpfl VarioLock64 middle strut is a frame system component for use with the VarioLock64 system. It has a specified length of 20 cm and is supplied without studs or push buttons. The component is identified by manufacturer article number BVL-X/MST/X020. Its net weight is 0.83 kg, and the delivery unit is one piece. As a frame component, it has no projection surface or projection area.