This product comes in authentic OtterBox retail packaging. The instructions for installation are included and it's relatively easy. The hardest part is getting the screen protector on correctly. Make sure your iPhone is completely clean and lint free before you start! When you're first sticking the screen protector on, don't put it down all the way until it is centered.
I love the green color. It's a bold lime green, but not too "neon". The green part is hard plastic and the black parts are rubbery. It fits the iPhone 3GS perfectly. It's also less bulky and more stylish than the OtterBox Defender. I almost never drop my phone, but I wanted some protection against nicks and scratches. This case is high in quality and it looks great!
I agree with the other reviews: the rubber cover for the headphone port is a little hard to open. I previously had the OtterBox Impact, but the whole thing is rubbery and lint/dust/sand got stuck all over it. This case is definitely an improvement.