Inline control, shut-off valves. Necessary for times when you want 
to disconnect a hose without deflating the bag.

Over-inflation protection is usually not needed if pressure from the source is at or below maximum bag pressure 115PSI (8 bar). Safety pressure relief valves will provide an extra measure of protection against runaway over pressurization caused by a high pressure regulator failure when the ultimate source pressure is higher than 115 PSI.