Description KEEP YOUR CHILD SAFE AND CONFIDENT: These 3mm thickened handy bike training wheels add the reinforcement clip to build the sturdy triangular design that helps learners develop a sense of balance usable on the bike, saves the children from worrying about the struggle because of the bike HIGH-QUALITY FLASH WHEELS: Non-slip, wear-resistant, stable, the support arms of the training wheels have 3.0mm thickness, it will be more safety and stability for beginners. The black wheels fit perfectly on any color bike. UNIVERSAL AND ADJUSTABLE: The support wheels fit 12/ 14/ 16/ 18/ 20 inch speed bikes with a rear-facing horizontal fork end, but not suitable for those with semi-horizontal or vertical dropouts. Cannot be installed on bikes with derailleurs or drivetrain EASY TO INSTALL: Included 2 x vertical support arms, 2 x wheels, 2 x nuts, 2 x bolts and 2 x washers Go and enjoy your first outdoor bike exercise with your kids INSTALLATION: 1.Connect the training wheel and support bar together. First put the screw, drive wheels, gasket, support bar and nut in order, then fix them with a wrench. 2. Attach the stopper block, remove the rear axle nut from the bicycle wheel, fix the pointed horn of the stopper block to the bicycle frame. 3 According to the size of the bicycle wheel, choose the location of the appropriate hole on the support bar. the training wheels should have a clearance of about 0.5 to 1 cm (1/5 to 3/5 in.) from the ground. Tighten the axle nut with an adjustable wrench.