KINGLAKE Professional Visible Cutaway of Challenge Lock for Training Skill with 2 Keys and 2 Heads Package includes: 1 x Padlock, 2 x keys It is transparent.You can know how the pins work when a key is inserted. Best Lock Training Trainer Skill for Locksmith 100% brand new and high quality.A big deal for you. By watching the movement of the pin you will gain a better understanding of how a lock works.