Training Wheels Little World Heavy Duty Rear Bicycle Stabilizers Mounted Kit Compatible for Bikes of 14 16 18 Inch, 1 Pair-Stronger Version Material: Metal and Rubber The bike training wheels suitable for Children's bicycles of 14"/ 16"/ 18" Bicycle training wheels features 5" Diameter plated steel wheels; Bracket: 8.6 x 2.9 x 1.1 inch / 22 x 7.5 x 2.9 cm This set of kids training wheels assist young learners until they have developed a usable sense of balance on the bicycle. Improve your child's safety and confidence without holding the back of the saddle Fitting type: Fits all single-speed bikes from 14 to 18 inches with horizontal rearward-facing track fork end, but not suitable for those with semi-horizontal or vertical dropouts