This item is the replacement arms for S500 and HMF S550 multicopter quadcopter. Also you can buy this arm to DIY your own multi-copter.
Strong and hard motor arms material (with built-in fiber glass tube)
Design with Dihedral angle, more stable, good for FPV
Light weight arms compare with DJI or HJ 450 frame
Length of the arm : 23.3cm
Carbon rod inside the Arms which used to make it stronger and hard.
2Pcs Replacement Arms