From the bulk of it, it's definitely magnetic. It has a balky transformer, and will do all "that 70's Fluorescent" behavior: flicker, hum, start hard in the cold, etc.
It uses the "rapid" or "programmed-start" wiring method, NOT "instant-start", so if you replace with an electronic ballast, select rapid or programmed.
I buy competent GE, Advance or Sylvania electronic ballasts on eBay.
One guy sells beautiful GE programmed-start ballasts for $4 each. Why? They are "2L" with a 71% ballast factor; they are designed to under-drive the tubes to give only 71% normal light. (This is intended to give lighting architects a way to fine-tune lighting intensity without changing number of fixtures). However an LED might not care.
That said, LED "tubes" are very confusing, which is bad, but good if you can sort through it. There are at least 4 kinds:
- Plug-and-play: These require the ballast to be present. Downside, you must maintain the ballast; upside, you can change back to real fluorescent, which are fantastic these days.
- Direct-wire (opposite ends): These require the fixture to be rewired and the ballast removed. You remove the ballast and wire 120V hotshot to each end of the fixture (hot on one end, neutral on the other).
- Direct-wire (same end): Same, except both hot and neutral are on one end of the fixture.
- Universal: This can auto-switch between being Plug-and-play, and direct-wire (opposite ends).
Obviously, there's big advantage in bypassing the ballast altogether; though rolling back to real fluorescent will be impossible at that point.
Also, you can never quite tell whether a tube will be single-ended or double-ended, the box will sometimes will say one kind and there'll be a note inside saying "Hup, we shipped you the other, just rewire". They don't think anything of telling you to rewire the fixture for their tube, since "they're supposed to last forever, right?" Well, in my observation the supply chain is so glutted with cheap Chinese that they don't last like they should.
So, while real fluorescents are not simple, they are not full of complications and surprises: the wiring is "exactly what it says on the tin". And a modern ballast for and with T8 tubes will beat an LED any day of the week IMO. Not for efficiency, but certainly for quality.
