The instructions and the full kit inside helps align and easily put the screen protector on the phone. It has 3 sets, in a box. My first one cracked after about 6 months of use. Not sure how, but the corner got cracked and it spread all over. So, I have no complains with having 3 sets per box for an affordable price. Even beginners can successfully put a screen protector with their kit and instructions. No problem with screen responding with this protector on. Will definitely recommend to others and repurchase.