Dave Brown 2 3/4" Lite Flites. They fit in the Bolly pant opening. Just barely, but good enough. I tried 3" DB LiteFlites. They had a wider hub i believe, Could not make them work.
The Mks from Central Hobbies will work, but dang pricey.

I use a 3" 6/32 bolt,washer,locknut combo for the axle and pant retention. Have to cut some of the length from the bolt. I have about 100 flights on the 6/32 bolt axle, no failure yet.