Compact in size and house in durable ABS enclosure. SMT technology This controller have a capacity to hold Max 9999 proximity card With in/out readers this controller control up to 4 doors Standalone system with group anti-passback function. Multiple group anti-passback function with PC software control (see Management Software) Programmable for different access level with different groups to maximize management control. For detail of this controller click here SY200NT Controller