JMT JMT Carbon Fiber Aluminum Tall Landing Skid Gear for DJI F450 F550 Multicopter Quadcopter FPV his products Do not included any electronic parts and the main frame kit,unassembly Attention Please:This product perfect fit for DJI F450 and Similar structure Frame,if you want to work with F550 or other frame,it need buyer to open Hole and Change install parts.Buyer have serious request or do not want to change by yourself,please do not purchase,thanks understand Screw and Washer is M2,Holder Bore Distance is 10mm,perfect fit for DJI F450 Quadcopter Frame