If you are looking to learn how to lock pick one of the methods to use is working with progressive locks. By Changing the number of pins that are inside a lock you can increase or decrease the difficulty to picking that lock. A two pin lock is much easier to pick than a five pin lock. A progressive lock set help you learn by providing locks that get progressively harder. This set includes a 2pin, 3 pin, 4 pin and 5 pin standard lock with Schlage Key way. Each lock is also laser engraved so that you can easily keep track of what pin configuration is inside. So you might ask why no 1 pin lock? Trust us you don't need it. Start at 2 pin.