Du-Bro Treaded Tire 2.5" \(57mm\) Part No: 250T. 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. These also have many more applications in school projects and various crafts. Diameter: 2.75" \(69.85 mm\), Axle Diameter: 5/32" \(4 mm\), Weight: 43grams/wheel, Width: 0.900" \(23 mm\).