The Anchor Adapter adds a Security Lock Slot to your laptop. It's designed for laptops that don't already have a built-in security slot. ^^ Works with Macbooks, Surface, Dell, Lenovo and all other major laptop brands ^^ Simply plug the Anchor Adapter into the 3.5 mm Audio Port (Headphone Jack) and turn the screw to install. Then attach your laptop lock to protect your device ^^ The lock slot is 7mm x 3mm and is compatible with Standard Size T-shaped Bar cable locks. Multplx compatible lock sold separately ^^ Patented design, it doesn't damage or alter the laptop's body unlike adhesive alternatives