ADJUSTABLE TRAINING WHEELS – These training wheels are compatible with 12-, 14-, 16-, 18-, and 20-inch children's bicycles. Designed with elongated mounting holes for easy installation and height adjustment, they help prevent rear tire lift and provide added stability through reinforced auxiliary support. MUTE FLASH WHEELS – Equipped with a magnetic dynamo hub that generates light with motion, these wheels require no batteries. The built-in LED illumination activates as the wheel spins, enhancing visibility and helping alert nearby vehicles and pedestrians, improving safety during evening rides. SUITABLE FOR BEGINNERS – Designed for young riders learning to ride, these stabilizers attach to the rear axle and work with steel-framed kids' bikes. Compatible with hub gear systems only. Not suitable for bicycles equipped with derailleur gears or gear shifters. STURDY STRUCTURE – Features reinforced steel mounting brackets that form a durable triangular support structure to resist bending and prevent rollovers. Includes high-density bearings for smooth rotation, shock absorption, and improved balance. DURABLE MATERIAL – Constructed from thickened steel for enhanced strength and load capacity. The wheel surface is made of wear-resistant PU material, ensuring quiet operation, long-lasting performance, and resistance to abrasion.