I was wrong about the first bar…
I made the assumption that it would be the same as the Robinson’s I fly regularly. However, the fully articulated 3-bladed system on the H125 wouldn’t be prone to mast bumping in turbulence, so it makes sense.
The first bar is power off VNE, so don’t go faster than this with full down collective or during an auto (125 knots)
The second redline is power on VNE. don’t exceed 155 knots.
RBS could occur above VNE, but probably won’t happen at 156 knots. There is always a safety factor built in, but pass this speed and you put the aircraft at risk.
The above pic is straight from the AS350B3 POH.