Anton V2 for me. came with a printer, 2 temperature pipe clamps, 5 hole bent probe for flueless fires, a 7 hole cooker/grill probe, standard flue probe and a LED sniffer. It does timed let-by & tightness with a print out, fan and gas pressures - working, standing, burner etc.. positive and negative pressure readings useful for testing the fan pull, the sniffer is really useful in safely detecting gas leaks. Great for recording flow and return temperatures + temperature differential. It makes filling out the bench mark a doddle. I've had it 6yrs with no problems and £120 a year for calibrating. Had a tetso before that when FGA's were not mandatory but it didn't do anything like what I can do with the Anton V2. I'm thinking of the Anton Sprint Evo 3 next when this one does eventually give up the ghost. Anyone used or own one yet and there thoughts on it?