The Kensington Security Slot Adapter securely attaches to your Ultrabook and other peripheral devices that do not already have Kensington's built-in security slot Simply attach the adapter with the included ultra-strong, industrial-strength adhesive and you’re ready to use a laptop lock to protect your investment against theft (lock sold separately) Compatible with Ultrabook and MacBook laptops Compatible with any tablet, simply apply the adapter to the back of the tablet and lock Security Slot adapter diameter: 1.5” (40mm) What’s Inside: Security Slot Adapter, tape, glue