Panasonic KX-TA624-3 Key Service Unit Release 3 (Refurbished)Panasonic KX TA624 3 initially configured with 3 CO lines and 8 extensions and can expand to 6 CO lines and 24 extensions. The Panasonic KXTA624 Advanced Hybrid System can answer the call for your business, home business, or high end residential home use. It is a modular system with a base configuration for 3 incoming lines and 8 stations. It can easily expand to accommodate up to 6 incoming lines and 24 stations with the addition of two plug in