RND Dock + 2600mAh NFC Standard Battery for Samsung Galaxy S4 (compatible without or with a slim-fit case) (black) Perfect replacement or secondary battery made specifically for your Galaxy S4 Smartphone. Power Protection Circuit included. Eliminates the hassle of removing your case. Supports majority of Cases. RND Power Solutions products comes in professional retail packaging and offers a 1 year hassle free warranty. 100% Customer Satisfaction is our Goal. PLEASE BE CAREFUL when buying products on Amazon and only buy from trusted sellers. Sellers without authorization may sell an inferior quality product carrying no branding. Examples of some trusted sellers would be RND Power Solutions and Amazon. Authentic RND Power Solutions products will have our branding on the product and packaging.