BudsGunShop.com - Compatible with 10 rd xd mag?

sorry it will not work that way. it slides on to a full size mag to extend the grip of a compact when using the full size mag. if you slide it onto a compact mag the mag will be to short to seat in the gun (it will block mag from being fully inserted)

Joseph - this is not a "mag extension". and does not affect the magazine capacity in any way. I is merely a 'grip extension sleeve' in that it fills the space that exist when using a full size mag in a compact pistol .. it merely extends the bottom of the grip enough to make the magazine seat more evenly with eh bottom of the grip.

Joseph, this will work only on a "Full Size" 10rd or standard capacity magazine to cover the extra metal of the magazine and complete the grip on a subcompact. Remember, "Full Size Magazines" Only (they do make 10rd Full Size magazines for sale in restricted states). An actual sub-compact magazine is already short and fits flush and will not need the extension as there would be no room to attach it.

To add to Randy I's correct information, this doesn't extend the magazine capacity it is only a plastic sleeve used to cover up bare metal on magazines that are longer than the standard grip frame. If a 10 round magazine is already flush fit there is nowhere for this sleeve to attach.
I believe Steve P frequently spams a lot of incorrect information in addition to the "Please click the green box stating it as the best answer" nonsense.

Yes it Allows you to use fullsize magazines in subcompact pistols comfortably.
Fits:
Springfield Armory XD 9mm Luger, .40 S&W