Probably got a price tag of over 150 pounds in started making my own like tosh cost around fifteen pounds
Mine must be a few years old now; still works perfectly. If I want a fast flow I just turn it up, if I want a lower flow, I just turn it down. It never messes me about - NEVER - and once calibrated when I installed it, it never needs calibrating again.
It may only have cost £15 and about an hour to knock up, but it's been a diamond.