Replace factory loading buttons, or install a loading button on factory long 10 round magazines when converting them to 25 round magazines.
 
Includes:  Ten BLACK loading assist buttons made of blued alloy steel (no loading tool).  
 
The loading assist tool and buttons work on the factory 25 round magazines and the much shorter 10 round magazines.  If you have the longer 10 round magazines (sized for 25, but pinned for 10, like sold in California or New York) then you can only install the buttons if the pin is removed.