This bike has a high quality ultralight aluminum frame and an inner wire designThe brake system consists of double Hydraulic disc-Brake. And 27-speed Shifters ensures total control in every situation.The 27.5-inch wheels and Lock out suspension fork make for a great ride experience on mountain roads, highways, and forestways85% pre-assembled,easy to assemble,free pedals,required assembly tools included.The 18-inch frame is suitable for a person 5'7"- 6' tall.Hiland 27.5 Inch Mountain Bike 27-Speed for Man with 18 Inch Frame Lock-Out Suspension Fork Hydraulic Disc-Brake