Endurance is critical. Consumer microSD cards do not specify endurance, so the actual endurance of a card may vary greatly, making the card's life highly unpredictable. Analysis of dozens of retail microSD cards in the market showed actual endurance can be as low as 10 Program/Erage (P/E) cycles. In addition, some consumer microSD card vendors understand the high, continuous workload of surveillance cameras and therefore explicitly nullify the card warranty if the card is used in a surveillance application. Don't risk losing critical security video. Trust WD Purple microSD cards, which have a specified endurance.