Crash Kit Main Blades Tail Flybar Set for Haktoys&reg; HAK448 4 Channel 16" RC Helicopter Package contents: 4 x main blades, 1 x tail blade, 1 x flybar, 2 x connect buckles, 4 x main grip set Compatible with Haktoys HAK448 4 Channel 15" RC Helicopter Upper blades and lower blades are NOT interchangeable.