Your model uses the Mag-Safe 1 adapter. 60 watt will work. Lot son fakes out there so go with a known reliable reseller
https://eshop.macsales.com/item/Apple/MC461LLA/?utm_source=google&utm_medium=shoppingengine&utm_campaign=googlebase&gclsrc=aw.ds&&gclid=Cj0KCQiA6Or_BRC_ARIsAPzuer8LfeQyOrPkmsDTbI_O_Lhzsvwx3uhddK89BdhewWfkYF1qOa9hsjkaArhKEALw_wcB