XJD Teen Mountain Bike engineered for youth. Sport streamlined design delivers exciting outdoor off-road adventures. Features: - Dual disc brakes –Responsive, stable braking on all terrains with low wear and long service life. - Front spring suspension – Absorbs bumps for smooth, comfortable rides on rough ground. - 21-speed gearing – 3×7 21-speed system easily handles hills, flats and rough trails. - Adjustable Height –Adjustable saddle height, grows with kids. - 2.09" wide thick tires & dual-wall aluminum rims – Enhance riding stability and grip, resist deformation and stand up to long-term use. - Integrated shifter lever –Smooth & easy gear shifting. - Easy Assembly – 85% Pre-assembled for quick installation. And referenceable installation videos & manuals Specifications: Available Size: 20 / 24 Inches Color: Black / Blue 20-inch: Fits ages 6-9 (Rider Height 45.3-55.1 inches) 24-inch: Fits ages 8-12 (Rider Height 53.1-61 inches) Why choose XJD? Lifetime Warranty & Premium Quality & Reliable After-Sales Service Guaranteed. Every inquiry gets a timely reply, and every problem gets fully resolved.