The Aqara NFC Card provides a convenient keyless entry solution for your home, allowing you to unlock compatible smart locks with a simple tap. This black rectangular fob is designed specifically for use with the U50, U100, U200, and U300 models, featuring high sensitivity induction that ensures a quick and reliable response whenever you reach your door. Measuring 42 x 26 x 3.5 mm, the card is compact enough to fit easily in a wallet or hang from a lanyard thanks to its integrated hole. The programming process is straightforward, though it is important to note that each card supports one-to-one pairing, meaning it can be linked to only one lock at a time. This makes it an ideal accessory for family members or guests who prefer a physical token over using a smartphone app to enter the house.