The Integral Locking System (I.L.S.) replaces the mainspring housing of the handgun and when engaged prevents the hammer from moving by locking the mainspring cap, making the gun inoperable. It does not require any modification to the handgun. Comes with two keys. No instructions included.
The mainspring cap pin is removed and put aside in order to replace the mainspring cap with the new one provided. Once the new mainspring cap is installed, the mainspring cap pin is NOT re-installed. When placing the mainspring housing back into the pistol, make sure the locking mechanism is in the unlocked position. You will be compressing the mainspring, (16 lbs on the Government model, 22 lbs on the Officer) so this will take some pressure.