This unit is NOT needed with some vertical fin installations. We installed the 70509 on a 1977 150M, and it bolted right to the existing plastic mount on the fin.
John B
26.10.2017
Used to install a Whelen 70509 Flasher in place of a rotating beacon on the top of the Vert Stab. Fit and finish is perfect and the captured nuts make installation a snap. But price is way too high. So only 4 stars.