Overview: The 2TB Purple Surveillance Internal Hard Drive from Western Digital is designed to withstand the stresses placed on it in a 24/7 surveillance system. With support for up to 32 high-definition surveillance cameras this 2TB hard drive can hold a large amount of data and gives you the ability to easily upgrade and expand your security system. Built for always-on surveillance storage applications AllFrame technology for reduced pixilation and video interruption Designed to support up to 32 HD cameras Caching algorithms specifically designed for security surveillance operation 2 TB capacity holds up to 400,000 digital photos, 500,000 MP3 files, and 240 hours of HD video. Specifications: 2TB Storage Capacity 3.5 Form Factor 6 Gb/s Data Transfer Rate 64MB Cache Surveillance Class Storage Supports up to 32HD Surveillance Cameras