One of the things that Jim Fox was keen on when designing Zeagle's regulators was that the service kits be able to cover the entire range of the line and that many of the parts were shared by various models. As such you'll find that the 345-1000 service kit (for Zeagle diaphragm regs) has all the necessary parts to service the Zeagle 50D 1st stage as well as the Envoy, Onyx, Flathead, etc. Right now I'm sitting in front of a whole tub of turret bolts specific to the 50D 1st stage, there is little worry about running out of parts in the near future.