Enhance your office communication system with the AT&T  1224/2448 Spirit 4 Line Expansion Card. Designed to seamlessly integrate with your existing telephone switching system, this expansion card is model number 60312A, with MPN 105468722, ensuring a compatible addition to your setup. The card provides a robust 4-line capability, allowing for simultaneous multiple calls without the need for a costly upgrade to your PBX system. It's an ideal solution for businesses looking to expand their telephone lines efficiently and effectively.