I purchased one of these about 8 years ago for myself and my wife. We both loved them. So when mine went out, I decided to reorder. The only complaint with this one, unlike it's predecessor is that it will not allow you to reset the parking distance from the wall if you need to be in close. With the prior unit, I could set it to let me come to within 6 inches of the wall. This unit keeps going red when I get to about 1 1/2 feet. I tried resetting it many times to no avail. If your garage space is really tight and you need to park really close, I'd suggest looking at other products.

This is the second Park Zone I have purchased for my aging mother who still drives. It makes her task of entering the garage and getting close to the end but not too close. The first one worked well for a number of years until she had a lapse and crunched the lower sensor with her bumper. It has saved numerous dents in the garage wall from her getting too close as had been the case prior to the Park Zone. The lights (green, amber, red) that are easily seen from the drives location make it easier to get close to the end wall without hitting the wall. I personally have driven her car into the garage and use the Park Zone myself to get close but not too close.

I tried this unit for about two weeks, and had to switch it to another location. Okay value at $23; but rather like the ceiling mounted laser idea.

PRO
Easy to install. Easy to use. Pretty accurate (+/-2inches).
Comes with a AC power adapter that I wasn't planning on using.

CON
Needs plenty of space around echo locator or their "ultrasonic transducer" (Also ping'g is audible and may by annoying if you're sitting in front of the sensor). I have it next to a garage/home entry door with a little traffic. This is a major problem, i.e., unit does not like things left in front of unit- like a bike or box. In fact, shoe-high boxes or other items placed unwittingly in the sensing range or left under the subject car may throw off the accuracy of this device. Unit is suppose to revert to "Default-Mode to check against such nuisances". It definitely does not like much people traffic in front of unit.

Batteries were suppose to last a year. I was in fact planning on running just on batteries; but, they can drained unexpectedly (Area around transducer needs to be clear by roughly 2x2ft in front of unit.

Conclusion:
I had to buy one of those laser systems for greater reliability at a comparable price. Also like the fact that it's more accurate. Almost guaranteed of a AC outlet on the ceiling.

Product: Park-Zone PZ-1500 Precision Parking Device, Dual Powered, 110V or 4AA Battery Operated (Not Incl'd)
Mfr: Measurement Specialties
Distance transducer to car: 3 ft (recommended 1.3-16)
Distance btwn transducer to floor: 1.8ft (recommended 2.3-3)
Times device had to be recalibrated: too numerous to count
Approach speed: Input power: AC Adapter

The first one I got didn't work correctly, it never would configure itself properly (kept blinking the red light). After getting the first one replaced, it seems to work pretty well. Makes backing the truck in super easy, which the old tennis ball doesn't help with at all.

Amazon is amazing in the return process though. They are very fast to ship replacements, and very graceful in the amount of time you have to return the old one. They provide an easy way of printing out a label too, the whole return process couldn't have been better.

This devise is really an amazing devise. It will allow you to park your car anywhere in your garage you please. It has green, yellow, red (stop) lights on it just like a typical red light. It works the same every time you park.

I have had one of the cheaper version (other brands) that only allow you to park a certain distance from the wall and that is not always handy. With this one you set you car any distance you want it in the garage and push a button to set it, and you are done.

My dad had one of these in the battery powered only, worked well, but every time battery went dead you had to reset it. This one work well and is powered by 120 volt so you never have to worry about a battery or having to reset it. *THIS IS A GREAT UPDATE TO THE BATTERY ONLY MODEL*