Installed easily, accuracy is good, connectivity could be improved. After a couple of trips usage on our travel trailer very happy with the purchase.

I wanted a TPMS system for my new travel trailer. If you've ever had a blowout in a trailer and did not know it until you heard metal grinding you'll know why. This unit is much cheaper than some of the more mainstream brands so I thought I'd give it a shot.

I've only used this once, but here are my impressions. It's cheap and it appears to work (with some qualifications). The manufacturer recommended I get the unit with the range extender. I did get it, but tried it out without the repeater. It did sort of work, but I had to move the display around on my dashboard to get all 4 tires to read out. And to me this uncovered one of the things I do not like about this unit (possibly the same problem other brands have). This unit will give you a readout whether or not it is actually receiving live data from the sensors. When I started driving, I saw 3 of my tire pressures and temperatures increase, but not my rear tire on the driver's side. It just read the original numbers. when I picked the display up and moved it to the left of the dashboard, it began giving live info. The problem is, unless you're paying attention you could be loosing tire pressure and not know it because there is no "live pulses" function that tells you you're getting live data.
Another thing I don't like about these kind of screw on sensors (and I think this applies to even the more expensive brands) is that you must basically defeat the Schrader valve in your tire when you screw the sensor in and hope the sensor does not leak from an internal defect or loosen up and leak (they supply lock nuts that are supposed to keep this from happening). Its a bit of a pain to put the sensors on, and if you ever need to add air to your tires you have to remove the sensor and then re tighten it and put soapy water on the valve to make sure its not leaking.
The display is small and can be hard to read, but not that bad. You charge the display unit using a USB connector and it has a solar cell on top that is supposed to keep it charged while you are driving. I've only used it for one short trip, so I have no idea how effective the solar charger is. I assume if this is a problem you can just plug a USB connector into the unit on your dashboard.
There is a high/low pressure alarm setting you can put in the unit. My tires are supposed to be 65 psi cold, so I set the low to 50 psi and the high to 70. The pressure in one tire reached 71 psi and the alarm went off immediately. So I think this unit will do the job as long as you insure you're getting live data. Its nice to get in the car and be able to make sure you've got proper tire pressure without having to measure them with a gauge first.

3 of the sensors worked fine, one had a dead battery. Like dead-dead. I measured 0.3V out of 3.0V so I don't know how this one passed any level of quality control. Other batteries were still 3.0V. An $8 battery later and all 4 sensors work great now. I carry an extra battery in my kit now. Hopefully it was a dud battery and this sensor isn't draining them. Will update if it is a dud.
Note that you can flick the valve stem and wiggle the sensors to wake them up after sitting a long time. My screen updates all 4 tires within 2 minutes before we get on the road. I added valve-stem-wiggling to my camper road-ready-checklist.

Works great, sensors connected themselves as soon as I installed them on the valve stems, solar is awesome. The instructions arent super clear and the setup user interface for changing parameters and units of measure isnt super clear. Once you get past that, cant believe how slick it is. I might add another for my trailer tires.

Overall, this is a pretty decent item. I've only had it for 6 months now, but I really like it. It's especially nice because it's pretty accurate and costs ~$50-60 (wait for a deal) and I don't have to waste money going to get new sensors replaced for $100+ a TPMS sensor. Overall, it was worth the purchase as it's very convenient to see the current pressure/temperature for each wheel (if you don't have that with your vehicle already).

This product works by replacing your cap for the air valve with a sensor and nut. Once the cap is off, you thread on the [locking] nut and then put on the sensor hand tight. You then "loosen" the nut which winds up using friction to keep the sensor tight in place so someone (without the included 1/2" offset wrench) cannot remove the sensor(s). It takes an extra 10-20 seconds to add air into each tire because of this mechanism, but it's not a big deal.

The unit itself comes with adhesive to secure to whatever surface you want which is very helpful so it doesn't move around easily. It constantly charges via the sun. Something to note: I believe the unit turns on when it senses vibration (via closing a door or starting the engine)--but can be turned on (e.g., the display) by clicking any of the buttons. It will then show whatever data was last recorded from your previous trip, BUT once the car moves it takes about 5 seconds of the wheels rolling to update the data (automatically) to the currents stats. Just be aware of that. It doesn't bother me, personally.

The description says it has an accuracy of +/- 3 psi. That's an absolute range of 6 psi--a lot of room for error for my liking. Despite that error being apparently similar to other items on Amazon, I have found with my trusted digital tire gauge that this unit reads +/- 1 psi most of the time. That's really good.

There's a lot of settings on the device that you can customize to your liking. Other reviews have stated that once it starts beeping (i.e., the tire pressure drops below a set threshold), the beeping will not stop until the pressure is increased. That is FALSE. All you have to do is hit one of the buttons on the top and it stops the beeping.

***Due to the small space you have to tighten/loosen the "security/locking nut", you need the included 1/2" offset wrench (feels like just sheet metal or the type of wrench that comes with furniture). I have an assortment of tools and cannot find a tool that would suffice. Maybe a small open-end 1/2" wrench that is bent or an open-end crowfoot could do it. But a flare nut crowfoot or standard open-end wrench will not do it. I cannot find the included wrench anywhere; so if you lose it, it might not be fun. I WISH THEY WOULD INCLUDE 2 OF THESE WRENCHES IN THE PACKAGE.