Datalocker Sentry K300 Encrypted Keypad Micro SSD Drive 256-Bit AES 256GB. The Sentry K300 is a platform independent, keypad, micro SSD drive that incorporates an OLED display to enable advanced security features. The display supports true alpha-numeric password-based authentication and a full featured on-board menu system. Users can use the visual, menu driven system to change passwords, set the password policy, and enable other security features without ever consulting a manual.