Bike Training Wheels for 12, 14, 16, 18, 20 inch Variable Speed and Single Speed Kids Bikes. Extension bolts are included to solve the problem of installing training wheels on bicycles with short rear axles. The training wheels are easy to install and remove, allowing parents to adjust the height as their child grows. The wheels are equipped with rubber tires that provide a smooth and comfortable ride. Constructed with a sturdy frame, these training wheels can withstand the weight and impact of outdoor use. The frame is designed to provide a stable and secure ride. Crafted with high-quality rubber materials, these bicycle training wheels are slip-resistant and wear-resistant, ensuring a stable riding experience for kids. These training wheels are popular with both boys and girls, making them a great gift choice for children. Color: Black Material: Iron + Rubber Package Contents: 2 x Screw 2 x Side Wheel Note: Only the items listed above are included. Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the actual product. Measurement error allowance is +/- 1-3 cm.