Feature These bulk pin backs are made of nickel-plated copper, durable and anti-rust. Smooth surface, sturdy, and lock your pins firmly without worrying about them falling off. Provides a replacement for torn screw or wrench locking mechanisms. Keeps your items securely in place during important moments. No need to lose any of your pinskeep them secure with this convenient set. Small screw pre-set for easy use; no more loose parts to handle. How to use: Insert the black screw into the middle hole. Use a small wrench to tighten half of the black screw to secure it. Attach the brooch or medal to be fixed through either end of the small hole. Then use a wrench to gradually tighten the black screw to ensure a firm hold. Item Type: Pin Keepers Material: Brass Color: Silver Type: A/B (Optional) Size: A Small 6x5mm B Large 6x9mm For more details, please refer to the photo. Quantity: 10 Sets Note: Size measurements are taken manually and may have a 03mm variation, which is considered normal. Due to differences in monitor displays, the picture may not reflect the actual color of the item. Package includes: 10 Sets x Pin Safe Locks