I dont know much about turbos but im lookin to buy a stage 3 turbo for my S2, the bloke says its for a S1/S2 and the spec is.....

Wet floating bearing
Compressor A/R .42
Compressor @ stage 3
Turbine A/R .48

Is this a stage 3 turbo from the spec what do i need to look at to tell the difference from a standard t3 ??

Any help would really be appreciated