RC airplane enthusiasts, these Heyiarbiet foam wheels are exactly what you need for smooth takeoffs and landings! The 3.5-inch diameter (90mm) gives you plenty of ground clearance while remaining lightweight enough not to affect your plane's performance. The PU sponge material is genius - it's super light but still provides enough cushioning for bumpy runways or rough landings. The plastic hub is durable and has that classic spoked design that looks scale-accurate on most model aircraft. The inner hole diameter of 3.9mm fits standard axles perfectly without slop or play. At 30mm thick, they provide good stability during ground operations. What I really appreciate is how these wheels maintain their shape without becoming deformed over time like some cheaper foam tires. The black color looks professional and doesn't show dirt too badly. Installation is straightforward - just slide them onto your axles and secure with your preferred method. They're perfect for electric models where every gram matters, but they're tough enough to handle the occasional rough landing. The open spoke design not only looks cool but also helps reduce weight further. I've used these on several different models from trainers to scale warbirds, and they perform consistently well on both pavement and grass surfaces. The pack of two means you have a spare if needed or can outfit multiple aircraft. Seriously, if you're tired of hard plastic wheels that transmit every bump or heavy rubber tires that affect your plane's balance, these PU sponge wheels strike the perfect balance between weight, durability, and performance - they're a game-changer for RC aviation!