Q: I currently have a (broken) Rena Flow 450 Type M2(S) Model 450 S. It operates an outdoor fountain that's about 5 feet tall. Will this pump be a suitable replacement for the one I have?
A: The old Rena Flow 450/2000 has a tube type intake that allows the unit to have two tubes attached, one inlet one outlet. If all you have is a tube attached to the outlet then RO2000S is a good replacement.
However, if you have a tube attached to the intake (also known as an inline application) then the only pump we sell like that today is the RO1100S-IL. This pump has an adapter that can be placed on the front of the pump to allow a tube to be attached. It is not as powerful so no telling if it work for you.