Any inline plumbing device will create a pressure drop, Example:ball valves, check valves, water meters, etc…
A simple rule of thumb, the higher the water volume running thru these devices the more the pressure will drop.
The Hydro Ninja has a proprietary self adjusting piston mechanism to help reduce any major pressure drops. Also when you purchase a Hydro Ninja it includes 2 orifice plate inserts – 1 High Volume and 1 Low to Moderate Volume. If there is ever any major fluctuation in your water flow you can simple replace or swap out the insert.
This is very helpful for seeing what type of meters are out there – Thanks!