Du-Bro Treaded Lightweight Wheel 4" \(102mm\) Part No: 400TL. Du-Bro Large Scale Treaded Lightweight wheels feature a foam interior yet have a tough and rugged exterior skin for durability. Excellent for paved runways! Hubs come with a 3/16" \(5 mm\) axle dia. opening and can be drilled out to 1/4" \(6.35 mm\). Features:
Lightweight
Shock absorbing
Fuel resistant
Built extremely tough
These also have many more applications in school projects and various crafts.