I found it difficult to install. At my age{75} the spring was hard to compress. I ended up inserting a small screw driver through the spiral of the spring and through the lower portion as it sat in a block of wood with a 3/8 hole in in . As I rotated the screw driver around the spring, it compressed it. Works great once installed. Easy to take apart , clean, and assemble to clean the gun.

Alan from Indiana, if you purchased a Mcarbo charging handle, you'd understand what this product is for. You don't need it for the OEM charging handle (that's why the product description says it's for **Aftermarket** charging handles).

There's a super easy way to install this thing. Use two allen keys or punches to "walk" the spring into place. Having some lube on the pins makes them easy to pull out and insert. Put the first pin below the point you want to lock at the midpoint of the spring, press down, insert the 2nd pin, press down, remove the 1st pin and put it above the 2nd, etc. Repeat until you have room to install the locking pin with no pressure or torque. No backplate or drilled piece of wood needed.

The product works great. The installation takes some time and patience but well work the effort. Love all the accessories i've added so far.

As I said, it's a simple, effective fix!