Yaesu Original CT-39A Packet Interface Cable CT-39 For Yaesu Tranceivers with 6 pin mini DIN Data jack. Fits many models including FT-450D, FT-8800R, FT-991 FT-817, FT-897D, FT-7900R, FT-7800R Pin out information included. For Hookup to TNC. Genuine Yaesu product. Check your owners manual for compatibility.