It is very suitable for RC beginner althougn F550 have simple design, with built-in circuit board for ESC power distribution, seldom parts but strong structure to let user more easier for maintenance. The mounting holes design can fit for different controller board e.g. KK, FF, , in the RC market, it can fulfill different kind of user need e.g. FPV. Recommanded Combination: Motor:/2216/2814 800KV-1000KV ESC:20A-30A Battery:4s 2000mah-3600mah Lipo Size:550MM(Wheelbase) Weight:448g Note:the thickness of the 4 motor arms are 5mm, pls use M3x8 screw for motor fixing. Colour:As Shown Material:plastic Package Contents: 1 * FPV F550 Hexa Frame Arm Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.