This is a set that can be purchased to go along with a Leapfrog Leapster, or Leapster L-Max. My son received a Leapster L-Max for Christmas, and we got this in addition to the game system.
The recharging kit has a rechargable battery pack that fits into the Leapster system, and then you simply dock the entire Leapster onto the charger- no removing the batteries! I love this feature, because there is nothing worse than having to go on a search for a screwdriver to try and wrestle the used batteries out of a kids toy. The station takes about 4 hours to charge fully in our experience, but it took almost a full 24 hours the very first time we charged it- this really tested the patience of my 4 year-old!
You also receive an AC adapter with this kit, so you can plug the Leapster into the wall and play like that as well. We have used that once or twice, but my son likes to walk around with his system, and having a short cord attached to the wall was frustrating for him.
The battery pack claims it is good for 300 charges, and although I can't comment on that necessarily since we are nowhere near that number yet, I can say that I would definitely recommend purchasing the recharger kit to go with a Leapster product.