New Custom made tool for replacing the mainspring with ease on a 1911 pistol and clones. Constructed of high quality acrylic. Included is a tool to remove the mainspring retainer pin if it is stuck due to dirt. Mainspring Housing not included. This is the easiest and safest way to remove or replace the mainspring. Just lift the knob, slide the mainspring housing upside down into the tool, lower the knob, twist the knob till the retainer pin is free (clockwise), remove the retainer pin (turn tool upside down as the pin will fall out), twist the knob counter clockwise, raise the knob and remove the housing with the spring. NO ACCIDENTS, NO LOST SPRING or PARTS. Will replace if received defective on arrival.