it has the dry bleed system, so it is suitable for cold weather use, not sealed though, but the drybleed is very effective. It is a balanced piston, and still very viable for use. Parts are also readily available. Second stage can be serviced as well and brought back if you choose. This is the Sherwood section so we aren't supposed to offer other brand options, but it can be used with any second stage on the market. There is only 1 that usually puts most regulators out due to a high IP requirement, but this can handle it.
As far as specific model, there have been so many subtle variations and I pay little attention to them, so someone with more direct experience can tell you exactly what it is, but it is under the same general concept as the Brut, but not sure which variant it is. Good solid first stage, not the highest performing, not the best for most hose routing, obviously not the most efficient or best for stage or deco use since it has the drybleed on it, but a very reliable solid first stage that works well in any environment I've used them in.