ASE S5 Moderator .30cal, but used on a .223 - 1/2x28 UNF thread to suit AR15/M4/M16 etc.....
Nice quality Mod, £80 collected from Petworth (30 mins south of Bisley) in West Sussex, or £100 sent to your local RFD from there. Currently off my ticket and at my local RFD (in Petworth), pic below:
Essentially the same as this: LINK, but a third of the price, and with a home sprayed coat of Duracoat matt black on it.
Not sure on age, I have had it probably just under a year, but got it second hand, they are stainless though so its not going to be rusted out! I am having a shuffle about to use the same mod on all my rifles.