Help Identify this Flash Hider or Compensator

[dms1]

Please help me identify this Flash Hider or Compensator

My dad passed away a couple of years ago and today I was going thru some boxes of fishing gear and came across this Flash Hider or Compensator. Can any of you identify it and and know how much it might be worth (if anything)

It looks like it is threaded on the end where the four slots are, but is not threaded at the other end. Also, I am not sure what that silver wire ring is for since there are no slots that go all the way thru.

The dimensions are approximately:
5.5 inches long
13/16" in diameter
Opening at end with silver ring 9/16"
Opening where slots are 7/16"

Pics

[Riverman]

Looks like it belongs to a Steyr Aug? Just an uneducated guess.

[dfletcher]

Not sure who makes it, but Austrian STG 58 is probably what it fits along with other FALs. Can you approximate the bore diameter?

http://www.dsarms.com/Austrian-STG58-Flashider-New---002C/productinfo/002C/

[G-forceJunkie]

Looks FAL to me. IIRC, they were used to launch grenades.

[QuarterBoreGunner]

STG-58, Major Stolle flash suppressor for the FAL/STG series of rifle. The silver ring is for retaining rifle grenades. The front is threaded for a blank firing device. The four 'prongs' are set up for wire cutting - you poke a strand of barbed wire between two prongs and twist the rifle to center the wire and then FIRE. Boom. Wire is cut.

See one here:

[QuarterBoreGunner]

Oh yeah, and worth about $15 to $20.

[SoCal Survivalist]

Never mind QBG explained it very well. Better than I have inleast.