Thanks to Bobby Hester (on another list, oh my
, the part, or equal, is NAPA EL-13A-2, I have also heard EFL300, EFL300BP. The flasher will handle lights up to 150 watts.
For those interested in low cost wing flasher setup, Bob's is as easy as it gets. The theory is run power to one of the three tabs on the flasher unit (20 or so bucks), then run power off the remaining two tabs, one to each wing light. Now, there is a B&C S700-2-3 switch in the system. The PDF is on Aeroelectrics website,
http://aeroelectric.com/articles/WigWag/WigWag.pdf. Go to your local Grainger store (or google Carling 4x850, double throw, On-none-On) and drop $4 for the switch. Now you have a wing flasher unit that weighs nothing and costs, with tax........something like $28, with no shipping, and found locally. One of those A+ deals.