The STC is for the Cessna 172. The tail installation satisfies FAA requirements and will enable subsequent tailBeacon installations to be performed on any “suitable aircraft” without STC as a minor alteration.
A suitable aircraft supports the installation of the tailBeacon without airframe modification.
See mounting template for a 1:1 scale drawing to help you make this determination.
For guidance on fitment and installation submit a photo of your aircraft rear position light along with the year, manufacturer and model to firstname.lastname@example.org