We have introduced all kinds of protective cases for iPhone 4 and 4S. But if you want to add some modules for more functions, the following Aeris Rail+ iPhone 4 case may be able to draw your more attention.
The Aeris Rail+ is a practical modular protective case designed for both iPhone 4 and iPhone 4S. The iPhone 4S case is constructed of injection molded ballistics-grade polycarbonate, plus CNC machined medical-grade stainless steel button cover in order to protect the iPhone 4 or 4S from bumps and scratches. Most importantly, the unique rails on both sides of the iPhone 4 case allows you to mount various accessories for more useful functions, for instance, the Visor, a set of front and back covers, the Kickstand, an iPhone stand supporting both landscape and portrait viewing modes, the Ride, a handle bar attachment for mountain bikes and etc. Apart from that, the custom cutouts allow you access to all the buttons and functions of your iPhone 4 or 4S.
At present, the designer of Aeris Rail+ is raising fund on Kickstarter. Pledge $50 will let you own the modular iPhone 4 case with the Visor kit and kickstand. If you’re interested, jump to Kickstarter official site for more details.
Additionally, if you need other options, you might like to check Flicker Classic iPhone 4 case, the mug styled iPhone 4 case and more via “iPhone 4 case” tag.