It's a name brand 9v battery, c'mon, does it really need a review?With that, here's my review. :)I use these for smoke/CO detectors and also in my alarm clock.This four-pack is the best price I can find unless a local store is having a massive deal. The free shipping and lack of sales tax sinks the nail into the coffin. Further, I saved an additional 15% (bringing the price down to $8.49) by signing up to have these delivered every six months. After the order is placed, you can cancel the subscription if you so choose.