Fantastic. It gives you the percentage for the battery...20...40...60...80...100. Other battery testers will show a battery as good when they aren't and you don't know where they rate. I threw away all mine that were rated at 20% and that was most of them.
First thing I did when it got here was go thru the box of saved batteries I had. It told me over half the batteries were less than 50% left so I threw them out. It is great because it tells the remaining battery power in a battery, not the present voltage like most others do. Does not test button batteries is only draw back. If you need to test button batteries get the MBT LA2.
The best battery tester I have ever used. It puts a load on the battery being tested and evaluates its voltage under load. A Voltmeter doesn't do that. It's well made and very dependable.