Description DUB-350T Treaded Wheels 3.5″ Low Bounce Features: complete with a sporty nylon metallic hub Works well on grass & paved runways. 2 per package thickness is consistent throughout the wheel Overview: 350T takes a 5/32 Axle (4mm). Du-Bro’s low bounce captive air wheels have flown on more airplanes over the years than any other wheels on the market! The wall thickness is consistent throughout the wheel giving you a balanced tire. Comes complete with a sporty nylon metallic hub. Works well on grass & paved runways.