Apricorn expanded its Aegis Padlock series of secure portable hard drives with two 750 GB models, one with 128-bit AES and the other with 256-bit AES encryption for a very high grade of data security. Measuring 19 x 84.5 x 120 mm, these drives have a keypad that lets users key in an alpha-numeric PIN. The drive also "self-destructs" (destroys the encryption key and permanently locks the data), when it senses a brute-force attack to gain access to sensitive data. The drive has an 8 MB cache, and uses USB 2.0 interface with a retractable cable. Backed by a three-year warranty, the Aegis Padlock 750 GB with 128-bit AES is priced at US $179, and with 256-bit AES at $199.