A heavier base pad drops the VP9 magazine cleanly after the release and closes the magwell funnel at the bottom when a magwell is fitted. The VP9 is the North American market name for the HK SFP9 -- the same pistol, the same magazine, the same base pad compatibility. For VP9 competition shooters, the base pad is the piece of the reload setup that makes the magazine exit reliable and the magwell funnel complete.
Confirm compatibility on the individual product page before ordering.