2 D-Clips, that screw to the rugged frame, fits for: ET5X rugged frame
ET4X D-Clips, for use of shoulder strap on Rugged Boot, fits for: ET40 / 45
PowerPack battery, order separately: expansion module, fits for: ET5X
ET4X, Expansion Back for PowerPack External Battery, fits for: 10'' ET40 / ET45