BW&reg; 4Pcs DIY Quadcopter Muiltcopter Replacement Frame Arm for DJI Flamewheel F450 F550 Frame Arm (white) Replacement frame arms for DJI Flamewheel F450 F550 ( 4 Pack) Made of strong materials, provides better resistance to damage on hard landings. Screw hole diameter: 2.5mm Frame arm size: 21.5 x 4 x 5cm / 8.5 x 1.6 x 2.0inch Weight: 40g / pcs; Color: Red, Black, White