i picked one up not to long ago from optics planet.over all its a good product.well built and heavy duty.but it is on the bulky side and depending on how you manipulate the charging handle it can get in the way.in order to install the mount you'll need the older style single prong carbine stock wrench similar to
this because of the design the newer style 3 or 4 prong stock wrenches wont work.after its all said and done,i wish i would have gone with the magpul ASAP sling plate.its a cheaper and maybe better alternative.
EDIT: torque values can be found
here in order to uninstall the castle nut you will need a carbine stock wrench,to reinstall the castle nut after installing the OEM mount you will need the older style single prong stock wrench and a torque wrench to get the castle nut to spec as per the TM.a little blue loctite 242 can be added to taste.