The all new HC460 and HC860 Hybrid Component Mobile DVRs are completely field serviceable and, once they are installed, any repair, upgrade or hard drive retrieval can be done without ever removing the DVR unit. The main board, hard drive, power control board and built-in Virtual Synchronized Mapping Module are all individual components, which come encased in a compact, vandal-proof, shock resistant and lockable box to ensure the safety and longevity of your investment. The HC460 has up to four camera and four audio inputs and comes with a 160GB hard drive with the option of a 320GB hard drive. The HC860 has up to eight camera and eight audio inputs and comes standard with a 320GB hard drive.