Worked great for 2 years. Then wouldn't measure the flow even with a new battery. Looked inside and little wheelt/fan like piece inside not moving. Used a small bladed (metal fingernail file) to loosen it. Then husband put a bit of slide lube on it, hooked up to reversed water flow and ran water. Hooked back up for correct water flow and works perfect. Saved $17 by not having to buy a new one yet!
It IS plastic but being a bit careful with it helps it last longer. We use it on our RV.

Definition - shocking a well: adding chlorine bleach after the pump was pulled, the purpose of which is to kill bacteria that may have been introduced

We had to shock our well as part of a project to get us more water. Of course, this is followed by a period of alternatively flushing the well and letting it recover over at least a day, in order to reduce the chlorine concentration until it is at safe levels. Since we knew how much water was in our well (how many feet of water times 1.5 gallons per foot), using this device was MUCH more accurate than just running the pump for a set period of minutes each time. Though it was by far the least expensive part of the project I personally think it made the whole process a lot easier to deal with and was a great tool in boosting my confidence that I'd not run the well dry - consequently burning out the pump (water keeps it cool).

Is it cheap plastic? Yup, so don't abuse it or purchase it thinking it's a pro-grade tool.

Is the display tiny? Yup, but still sufficient and easy enough to read.

Are the buttons marked? Nope, so read the little pamphlet it came with or experiment - there are two buttons. How hard can it be.

I'd definitely buy it again.

Liked idea of knowing how many gallons of water I use when watering outside . We have a well. And when filling rv fresh water tank. Works as expected just not sure how often I'll use it but for the price Iam glad to have it available

Got it to know how much water i put into the pool. Works easy enough. I can't say how accurate it is.

Works well but I've bought 3 (broken two) of them. It will break if you "bend" it while disconnecting or while pulling the hose too hard. I've bee looking for a similar flowmeter that is made from metal but they are all very expensive.
So I've bought a 6" hose connector extension with a coil spring reinforcement that I hope will take the bending instead of the flow meter, or at least spread out the side load on the device. I've attached the extension to the faucet and placed the flowmeter at the end of the extension, then I'll attach the hose to the meter. (https://www.amazon.com/gp/product/B08D3G2GQH/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1)