The V-2926 Option Board provides enhancement features for the V-2924A, Flexible Architectural Number Plan, PC Compatible Programming Port with Windows Based Programming Tool, Enhanced Caller ID, Real Time Internal Clock For Printer Output, Secondary Serial Port, User Defined Page Groups; Computer Requirements: Hardware : 80486 (higher is recommended), Hard drive with 20 Mbytes free, Mouse, 8 Mbytes of RAM (more is recommended). Software: MS WindowsTM 95, MS WindowsTM 98 and MS WindowsTM NT; Shipping Weight: 3.5 lbs (1.56 kg)