A versatile, low-maintenance mountain bike with an aluminum frame and 21-speed drivetrain, perfect for city and trail riding. Offers two sizes and arrives 90% assembled. Robust Frame For Adults: Aluminum frames deliver great performance, rust resistance and weight. Perfect for speed, trails, or commuting, providing absolute control Versatile 21-Speed Drivetain: Equipped with a 21-speed drivetrain, adult bikes offer a variety of speed options for a flexible riding experience. Easily adjust the gears to suit your preference Smooth City Commutes: This adult mountain bike is your reliable companion, ideal for relaxed city commutes and enjoyable rides on easy trails. It transitions seamlessly between city streets and scenic trails Dependable Disc-Brake System: Disc-brakes deliver reliable stopping power, making them easy to maintain and adjust, ideal for beginners learning the fundamentals of brake control in outdoor environments Choose Ideal Size: Tailored for both men and women, the 26″ adult mountain bike fits riders between 5’4’’-5’9’’, while the 27.5″ bike fits riders between 5’8’’-6’5’’, 90% pre-assembly and the tools provided