Non-electric model Features: PROFESSIONAL 21-SPEED SHIFTING SYSTEM: Using professional's front and rear derailleurs and trigger lever, this mountain bike can easier to adapt to different terrain with quick, precise gear changes. All-terrain tires can conquer gravel paths, dirt paths, and rocky roads. POWERFUL SHOCK ABSORBING AND BRAKING: The shock-absorbing cushion is matched with a thickened shock-absorbing front fork that is fitted with a double shock absorption effect. Mechanical dual disc brakes have a strong braking force and can provide a better braking effect than other brakes, which increases the safety of cycling. COMFORTABLE RIDING EXPERIENCE: Lightweight aluminum alloy wheels with specially designed spokes can better reduce wind resistance during riding. The lock-out suspension fork handles bumps and dips for a smoother-feeling ride. FOLDABILITY & ADJUSTABILITY: This foldable bike features a quick-release clamp that allows you to fold the bike quickly, which is easier to fold and stow in a corner of your apartment or your car trunk taking it with you anywhere. In addition, with a quick-adjust seat post clamp, you make easy adjustments seat to the right height. EASY TO INSTALLMENT: The 26/24-inch bike arrives with 85% assembled. You only need to assemble the handle, cushion, front wheel and pedal, adjust the brake and gear to complete the assembly. Please contact me if you encounter any problem that cannot be solved. Specification: Bike Type：‎Mountain Bike Age Range (Description)：‎‎Adult Number of Speeds：‎‎21 Color：‎‎Black/Red Wheel Size：‎‎24/26 Inches Frame Material：‎‎Carbon Steel Suspension Type：‎‎Dual Special Feature：‎‎Double-Kill Disc Brake System, Thickened Shock-Absorbing Front Fork, Foldable Design, Adjustabke Seat, 21 Speed Professional Shifting System Included Components：‎‎assembly tool, mountain bike Size：‎24"/26" Brake Style：‎‎Disc Style：‎‎Portable Suggested Users：‎unisex-adult What You Get: 1 x 21-Speed Adult Foldable Mountain Bike