"A rather good bit of kit for plumbers. Not something a DIYer would buy, but for a professional heating & plumbing engineer this is a good bit of kit. I've been using an old u gauge and it's done well, but it was time for an upgrade. This dual input gauge is accurate (to o.o1mb) and is well made. The readout is clear and simple to use. The price is very good in comparison to trade counter equivalents and the quality of the unit is very high. Overall I'd thoroughly recommend the TPI dual input manometer, you won't get a better gauge for the money."