Camera help pleazzzz!!!!?

i was ordering a charger for my casio exilim. here's the picture to give u an idea a href="http://www.onecall.com/product/Casio/Exilim-EX-Z75-Silver/Digital-Camera/_/R-89924." rel="nofollow"http://www.onecall.com/product/Casio/Exi…/a so i was shopping for a camera on ebay and i think i found one that fits but im not sure. what is an mAh and do they have to be the same???