kids bike 1, with good quality 2, safety design and advanced technology 3, competitive price ... . thickness is 1.0mm,argon-arc welding/CO2 welding. 2.Axle: B/A Axle, British System, BLK/UCP 3 ... .Brake: F Caliper Brake ED thickness is 2.5mm/V brake; R Caliper/Band Brake/Coaster Brake/ ... .Training Wheel / Leg: coloured / Enhanced type, thickness is 2.5mm,ED. Side Stand: Φ8.5,ED ( jus for 20") Quantity; ...