Original Rock Knocker:
8" x 18" Rubber Flap
We Recommend for:
64" Wide Cars
28" Tires
Double D Rock Knocker (Most Popular Model)
10" x 18" Rubber Flap
We Recommend For:
72" wide cars
30" Tires
Rock Knocker PRO
10" x 20" Rubber Flap with Dual Mounting Brackets
We Recommend For:
32" Tires or Larger
Racers or those who ride extreme conditions