I was hesitant in buying a tester, since the "test" is just plugging the cable in. I'm glad I did. I found an intermittent short by wobbling the DIY cable plug end when testing. I may have never found this issue otherwise.
I finally purchased this cable tester after I discovered a data error was the result of having a bad connection. In the past I just assumed all my crimp or punch down connections were good, but that is definitely not a safe assumption. I highly recommend this tester as it quickly and easily lets you know if there are any connection problems.
Not the best tester in the world, but OK for the price
This tester has issues. You cannot turn it off. The thing is supposed to turn off automatically, but I did not witness it turning off the time I used it. I went to bed and it was still on in the morning! I checked it when I got home from work the second day I had it, and it was finally OFF. Why don't they have an on/off switch on this thing? Ridiculous! I suspect the only reason it actually finally turned off is that the battery went totally dead, used up by the LED's which remain continuously on. If I find out differently I will write a new review, but so far this is a big disappointment.
Works perfectly. Test only takes one and a half seconds. Beware, came with a bad battery. It was showing a low battery (via the indicator light) on the first use. Worked for maybe 100 tests and needed a new battery.
It's still a great single-purpose tester, and I don't think it deserves fewer stars just because it came with a crappy battery. Just get a high-quality 9V battery if you purchase this.