RC hobbyists, this is for you! This is a 10-pack of high-quality 5x11x4mm ball bearings (that's 5mm inner diameter, 11mm outer diameter, 4mm width). They're precision-made from Chrome Steel (52100/GCR15) to ABEC 3 standards for smooth, high-speed rotation. The key feature is the hybrid seals: each bearing has one rubber seal and one metal shield to keep dirt out and grease in, making them durable for off-road and on-road use. These are direct replacements for a ton of popular RC car part numbers from brands like Axial (AXA1221), Arrma (AR610019), Losi (LOSA6947), HPI (B022), Tamiya (58041, etc.), Traxxas (4611, 5116), and Team Associated (25239, etc.). Having a 10-pack is super handy for rebuilds, upgrades, or just keeping spares in your toolbox. A great value upgrade to keep your RC rig running smooth and fast.