1.Size:12" 14" 16" 18" 20" 2.Bike Frame: steel and painting, argon-arc welding or CO2 welding 22X0.8-1.5mm 3.Bike Fork: steel and painting, co2 welding steel /suspension fork 22X0.8-1.5mm 4.Crank:one piece crank ,CP or ED or UCP; 5.Part to tighten the seat tube: very easy to assemble and tighten; 6.Brake: F/R Caliper Brake or R band brake or V brake or foot brake; 7.Handlebar and stem: 4-points handlebar,CP, argon-arc welding 22X0.8-1.5mm; 8.Tyre: 12"x1.75,16"x1.75, 20x1.75 or 1.95 2.125 2.4 air tires or EVA tire; 9.Saddle: good leather, common or spring /plastic/imitation leather/ plate PVC 10.Rim: 12" 14" 16" 18" 20" steel alloy or aluminum or plastic; 11.Chain wheel & crank: 12"24T 89/1628 102/20"28T 127 CP/ED 12.Flywheel: 16T/18T/20T Brown/Black/CP; 13.Mudguard: plastic,steel ,CP; 14.Chain: full chain or 9-form chain cover; 15.Pedal: plastic, with reflector, without ball, PP/TPE/ALLOY; 16.Paint: painting; 17.Color: red, black, blue, green, yellow etc. any color you like; 18.Attachments:flag, the covers of the wheels, training wheels,tool box, basket;