Installation of the Sigma Tek 1U619-( ) VHF COM/NAV/ATC Radio Control Panel with Collins VHF 22(C/D) radios to provide 25kHz and 8.33 kHz channel spacing in Cessna Airplanes listed on the attached FAA Approved Model List (AML) No. ST00831WI, dated November 4, 1999, in accordance with Cessna Aircraft Company, Master Document List No. CF90055, Revision B, dated October 21, 1999 or later FAA approved revision. View PDF on drs.faa.gov ↗

The STC PDF is authoritative: installation instructions, ICA requirements and limitations.