The Western Digital 3.5" WD40PURX Purple 4TB SATA 64MB Cache Surveillance Hard Drive is a reliable and high-quality storage solution for surveillance systems. With a storage capacity of 4TB, this hard drive provides ample space for storing large amounts of video footage. The purple color and WD Purple product line indicate that it is specifically designed for surveillance applications, offering features such as AllFrame and Advanced Format. The SATA III interface ensures fast data transfer speeds, while the 64MB cache enhances performance. Made by Western Digital, a trusted brand in the industry, this HDD is a dependable choice for storing and accessing your security footage.