whats this air filter called. mu 80 lowrider had one when i bought it in 84 untill i changed to s&s carb ive still got the original carb in the shed

 

It looks a lot like an earlier Custom Chrome or Drag Specialties "Dragtron" I had one on my Evo, but obviously your bike is a little more vintage. If your going to buy one, I highly reccommend the "Dragtron II" air cleaner. I read some Dyno tests on it back in the day, and it was at the top of the heap with a K&N air filter insert

Drag Specialties Dragtron Style Air Cleaner - DS-288999 Harley-Davidson Motorcycle - Dennis Kirk

Drag Specialties High Performance Dragtron II Air Cleaner - DS-289044 Harley-Davidson Motorcycle - Dennis Kirk

 

I can't remember the name but I had one on my 1967 XLCH back in the 70's on a Mikuni 38 carb. They were a free breathing air cleaner. I'll have to check out some of the vintage places to see If I can find the name.

 

It's a Dragtron

HARLEY 29002-85T AIR CLEANER FILTER KEIHIN 16415S4 49-0028 Dragtron Style | eBay