save your money. $35 + shipping,,,forget that.
things you need,
#1..shortened grip screw. if you have an after market grip you may already have a short grip screw. I know the Moe grip screw work for this!
#2..1/4x28 tap. forgot what I payed for this but it was just a few dollars.
and go here.
I did this and added a JP yellow reduced trigger spring and the JP red heavy hammer spring (JP's enhanced trigger kit $15-$19).
ended up with a 4lb trigger pull and almost no creep. but keep in mind this mod does nothing for the trigger reset travel!!
in total this mod cost me around the same price as what joebob is selling. but its way more then what you get from joebob for the money!