These fit 1-1/4" to 1-3/4" diameter sliders. Contact me if a larger diameter is needed. When I searched mud flap's recently I discovered that if you use a nice thick universal one (not the ones that contour to a fender or bedside) you'll end up with a heavy duty mud flap that's something like 12" x 13" and can be cut if needed. They are square and perfect for these brackets. All high quality mounting hardware included.
use a flap like this style