material:tonkin bamboo length:39"/100cn Spine rate:30-55lbs Package:40pcs Product features: u this product is refined through a series of complex processes, such as carbonization, straightening, polishing, painting and grooving. u after high temperature carbonization, the bamboo shaft is strong and tough, its color is natural brown, and its appearance is naturally retro. u mechanical and manual multi-channel straightening treatment can effectively alleviate the back bending and re-deformation of the arrow shaft under the condition of good shaft straightening.