Seems to work well. Using it on a small HF Predator motor and no complaints about it thus far. I like that it has a replaceable battery which will hopefully mean it is not a throw away unit.

I bought this for the replaceable battery, as all the other cheapo units' batteries would die after a couple years, and I wanted to be able to just slap in a new battery instead of installing a new unit. The tach seems to be accurate, it shows my generator is within about 100 rpm of 3600, but what I really like is the service indicator. You basically just enter the hours when the next services, and then a service indicator turns on when it gets to that. It's simple to use, it gives you the option to turn it off to save batteries, but you can just leave it on all the time and the battery should last about 4 years with it on according to the manual (I'm at a little over a year now with no issues). It just reads the hours when the engine is off, and when you start the engine it switches to rpm.

I think it might be a little more vibration sensitive than the other cheap sealed units, when I first mounted it to my generator I just screwed it onto the cooling shroud on the engine just like other ones I've used, ran the generator for about 4 hours and it only counted 1.5 hours. I moved it to the frame on the generator and it seems to be fine now. It comes with a velcro mounting (so you can pull it off to access the battery), I didn't use the velcro mounting but that probably absorbs a lot of vibration.

Used on a 2003 V-Star 1100 to help with tuning. Only thing i do wish is that it would turn itself off, but it's fine.
The . 5 second averaging actually makes tuning easier.
Plenty of length for whatever you're doing.

Works well but isn't exactly accurate but does the job

Delivered and worked as expected. Used to tune in RPMs on snowblowers. Did not have to wrap it around spark plug wire to much to work. Does what I needed, works well.