Du-Bro Low Bounce Smooth Wheels are Perfect for Trainer, Sport, Scale or Pattern Aircraft Models. FEATURES: Low-Bounce, Non-Treaded Rubber Tires Nylon Hub for Longer Wear INCLUDES: Two 3 1/4" Low Bounce Wheels SPECS: Width: 1 11/64" (30mm) Weight per Wheel: 3.07 ounces (86 grams) Center Hole Diameter: 5/32" (4mm) Outside Diameter: 3 1/4" (83mm) COMMENTS: Hubs fit 5/32" axles. May be drilled out to fit 3/16" axles maximum. NMH 3-5-92 upaxy5/23/98 Updated JPG 3/29/02 ir/jl