*Click on thumbnail to view full size picture* PRO STOCK TRACTOR: Originates from 1/16 scale 2 wheel drive tractor WEIGHT CLASSES: 3lb. & 5lb. MAX. WHEELBASE: 8" LENGTH LIMIT (Center of rear axle forward): 10 1/2" MAX. NUMBER ENGINES: 1 MAX. ENGINE DISPLACEMENT (Cubic inches): .051 NO THROTTLE CABLE ALLOWED TIRE DESIGN: Black rubber only 35 durometer or higher MAX. TIRE SIZE: 1 5/8" x 4 1/4" MAX. HITCH HEIGHT: 1 1/4" MIN. HITCH LENGTH (Center of rear axle to back of hitch hole): 1 1/8"