Strap Lock Pins Pull Type Set of 2 Silver Can be used to prevent your valuable instrument from falling. Suitable for various instruments such as electric guitars, electric basses, and acoustic guitars. Installation: Secure the pin to the instrument body with a screw, then attach the lock plate to the strap. How to Use: Use your thumb to press the screw head of the lock plate, and use your index and middle fingers to pull the disc part of the lock plate to attach and detach it.