I have found the rear stabilizer jacks pickup a lot of heavy dirt and mud even when using regular mud flaps mounted directly behind the tires.  By hanging this short flap directly in front of the stabilizer jacks, much of the heavy dirt and mud is prevented.  As dust will still collect on the jacks, its best to use a dry lubricant to lube the screw and bushings.  I used a length of slotted angle iron to mount to the trailer and the flap.  I bolted the angle iron to the trailer by removing one of the bolts from the stabilizer jack and sliding the angle iron between the trailer frame and the jack mounting flange.  Then replace the bolt, the single bolt holds the small flap with no problem. My flaps are made from cutting a larger mud flap I had on hand.  My flaps measure 8"x24"x1/2"

CLICK any picture to enlarge