Thread Conversion Adapter M16 to 1/2x20 UNF

Thread Conversion Adapter M16 to 1/2x20 UNF,

GSG402.00.14 Adapter for GSG522, GSG-15, GSG-16, STG44, Mauser AK47 Omega, Mauser M16, Thred forward 1/2"x20 UNF 

GSG411.01.12 Convert threaded barrel to ½x20 TPI (UNF)
GSG411.01.28 Convert threaded barrel to ½x28 TPI (UNEF)
GSG400.32.12.1 Original Muzzle Cap, (This one you missplace during you use the Conversion Adapter :-) )