Bike Training Wheels for 12, 14, 16, 18, and 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 children. These training wheels are popular with both boys and girls, making them a great gift choice for kids. Color: Black Material: Iron + Rubber Package Contents: 2 x Screw 2 x Side Wheel Note: Only the items listed above are included; other products are not included. Note: Light reflection and different display settings may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm.