Apple Lockable Cable Fastener $5.00 New and sealed! Apple Lockable Cable Fastener quantity Add to cart Add to Quote Continue Shopping Categories: Cables & Adapters (G3 to G5), Cables & Adapters (Intel) Description Apple 600-8821-A Lockable Cable Fastener. I believe this to have come from the G4 era, but can be used with any cabled accessories such as keyboards, mice, speakers, etc.