This product is exactly what it presents itself as, and it makes me wonder why they aren't more common. Not only does it more than double the amount of time I can work away from a power supply, but (as I say above) it won't be obsoleted when I buy a new laptop someday. There is a huge selection of tips that make it seem like this would work with just about any laptop (I'm sure it's not really true, but it seems that way), and my biggest challenge in figuring out which one to use came down to the fact that there were actually two that work acceptably, and I didn't know which one to use!My guess is, if you think you might want this, you'll be happy if you get it.