We picked up manufacture of these from Dawson Precision-- they are the exact same aluminum shock-buffer 'aluma-buff' design.
 
For 1911 and 2011.  Shorten your slide stroke, deaden the shock of steel on steel, protect softer shockbuffers.  CNC machined from aircraft-grade aluminum.  .100" thick.  Each "3 pack" has 3 alumabuffs in it.  Gunsmith installation recommended.   OEM packaging.