There are a few different types of access control systems on the market including magnetic locks and cloud-based systems, but proximity cards are definitely one of the most affordable and easy-to-use options. Proximity cards work by radio frequency and can be programmed to work with pretty much any access control system. They’re also very durable, so you don’t have to worry about them breaking or being damaged. Furthermore, proximity cards have many security features built-in, such as encryption, making them very difficult to duplicate or counterfeit.