The picture of this replacement battery is inaccurate - my daughter has uploaded some photos of the inov8 product.
I would strongly recommend Coolpix 8800 and 8400 owners to stay away from this battery.
I have now bought two - the first one would not charge in my Nikon charger, so - on advice from inov8 customer support, I returned it to Amazon for a refund, and bought another from an Amazon Marketplace merchant. I should stress this was not Purely Gadgets. The second one would not charge either. I rang the UK importer to discuss the problem. They promised to send me an Inov8 charger. No sign of that after two weeks. But even if I could charge the battery in the Inov8 charger, if (as it appears) the battery does not match the Nikon charger, what are the chances of the battery working in the Nikon camera?
After several days of googling, I have not come up with a single satisfied customer review for this product.
It is a paperweight, and not a very heavy one.