ARCA and PIC Glenwood Model A.  BOTH ARCA and PIC/ARCA fit both Late Gen 1 and Gen 2 Ruger Americans. 
 
Awesome for Lasers
 
The earlier Gen 1 models with the one piece stock/magwell area, will require a more custom install, but is still an option. 
 
Fits both Long Action and Short Action
  
Aircraft Grade 6061-T6 Billet Aluminum
  
Designed and hot cerakoted to match the coating of all three Gen 2 barrels.
  
Does require drilling holes, but is very straight forward.  Instructions Included.
Stainless steel hardware included. Rear back stop designed into the rail, or front stop, if you mount it backwards.