It is transparent.You can know how the pins work when a key is inserted.Best Lock Training Trainer Skill for LocksmithBy watching the movement of the pin you will gain a better understanding of how a lock works.-Powerful forcing with wide swinging spectrum for effective working-Indispensable for ironmongery works-Great universality to suit various types of locks-Uneasy to get out of shape、 to get rusted or to collapse-Lightweight and compact to provide great portability and to save space-Chrome-plated gun body for long service life Package includes: 1X Manual Lock Gun、