Kensington Microsaver Retractable Portable Notebook Lock & Cable/Security Device for Mac or PC - 64149 Kensington Edge: Retractable, portable 4' security cable lock combines notebook security with an easy-to-use design. Strong, slim 4-foot cable stows in easy-to-carry case Patented T-bar lock provides most secure connection to Kensington Security slot (found in 99% of laptops) Easy to use computer lock with no screws, messy glue, or brackets to install Only retractable security cable designed for the mobile user