The Internal 4Tb WD Purple 3.5" is a high-performance hard drive designed specifically for surveillance systems. With a massive 4 terabyte capacity, this drive can store large amounts of video footage without compromising on quality. Its advanced technology ensures that it can handle the demands of constant video recording, with a low noise level and low power consumption. The drive is also built to last, with enhanced durability and reliability features. Overall, the Internal 4Tb WD Purple 3.5" is an excellent choice for anyone looking for a dependable and efficient storage solution for their surveillance system.