E-system: Campatible with Bafang M510 and M600 motors. Battery: The internal battery is Reention Rhino7 battery case. Perfect for: All mountain riders. Tires: Designed to work with 29*2.35'' tire or 27.5*2.8'' tire. Cable routing: All internal cable routing. Internal dropper post routing. Dropper post is 31.6 diameter. Material: High Modulus Carbon Fiber