It's a must have tool if you're dealing with 9V batteries, to be used in audio and music equipment. At first sight, is a bit bulky and chunky but it can fit easily into travel bags and gear bags. It's weight is also negligible.
It's smart charging comes very handy and especially the LED functionality is super useful when it comes to onstage (sound checking, setting up) usage. The charging times, at least for one battery that I tested are pretty good! A great value for money.