This copter uses several ideas to improve strength and conformability. The arm tube top left and right bottom is one long tube, the top right and bottom left are half tubes but they a mounted inside a center element that joins all tubes together. The arm tubes are maximally reinforced and when the copter is crushed it is very likely to survive. Simple one nut removable landing gears, battery mounted on top, top mounted power distribution board and removable section of the flight controller mounted in the nose of the copter greatly improve convertibility. Despite all these features the copter weights only 730 gram. The copter uses 15mm tubes for its arms.