Transparent design， when the pins moving up and down as the key slides into and out of the lock，you can see clearly how the lock worksIt comes out in perfect smooth working condition with no loose parts or pinsLock with open chambers on all the moving parts that You can see clearly that how the pins work when a key is insertedDesign for learning lock picking，excellent teaching & training tool for beginnersPackage includes: 1 Clear Practice Padlock + 2 keys + 12 Pc Lock Pick Set