Those are basically knockoffs of the mfw vario footpegs but presumably made in China and cost less than half the mfw. I've looked at those before and they are a good alternative except how they keep from rotating for adjustment is different than the Varios which use a mating castle nut arrangement between the hinge piece and the arm, where is the knock-offs I believe have a hole and pin arrangement to keep them from rotating which could shear off if not made from decent SS and the aluminum is low grade. The MFW could never shear and made from aircraft grade materials

 

I adapted buell drop pegs years ago. I still have not figured out what to do about the height of the rear brake pedal.

 

Going from memory back a dozen + years ago, the following steps are in the correct direction

remove cotter pin and lower double but

trim off about 5 mm of threaded rod so rod does not impinge on clevis; no need for double nuts

drill small hole in rod for safety wire rather than use cotter pin and adjust pedal down to taste

I'll check when in my shop and take a picture and post it...