 "WD Purple WD10PURX 1TB Surveillance 3.5" Internal SATA Hard Drive"
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                Overview:
The 1TB 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 1TB 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
1 TB capacity holds up to 200,000 digital photos, 250,000 MP3 files, and 120 hours of HD video.

Specifications:

1TB Storage Capacity
3.5 Form Factor
6 Gb/s Data Transfer Rate
64MB Cache
Surveillance Class Storage
Supports up to 32HD Surveillance Cameras

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 "WD Purple 2TB 3.5" SATA3 HD CCTV HDD/Hard Drive WD20PURZ"@en WD20PURZ LN82090 | SCAN UK"@en
"2TB WD Purple WD20PURZ, 3.5" AV Surveillance HDD, SATA III - 6Gb/s, 5400rpm, 64MB Cache, NCQ, OEM                   "@en 