Overall, whatever this particular company produces, from batteries to chargers, is of excellent quality without any exaggeration. The charger has the ability to charge 4 AA or AAA batteries separately, with a discreet charging process for each one. Personally, I bought it because it can also charge 9V flat batteries and it does it perfectly. I don't give it 5 stars only because it's not a fast charger and especially for the 9V batteries, it takes 24 hours to charge them, which is a lot if you need them at that time. As a positive aspect, charging them in this way extends their lifespan since they don't heat up.