Large injector, suitable for a big stationary boiler, portable engine or traction engine (and probably something up to two foot gauge locomotive). No.5 Buffalo injector, it features a moveable delivery cone allowing it to be set for working pressure. I've had it salted away for some years, having been told by somebody else who uses one (on a 15 inch gauge locomotive) how good they were. Since the 12 1/4 Pacific is about the only thing I've got big enough for it (and it's got a pair of new Penberthys on), it's time for it to go!
I haven't tried it but it appears complete and unmucked about with. Lever moves freely.