Features:Brand new and High quality.This training kit is great for beginners or experts who are trying out new helicopters or new set-ups. It helps balances helicopter and it greatly prevents blades or other expensive parts from tilting and hitting the ground or any obstacles， thus saving costly damage. By using the training kit， beginner learn how to safely land RC helicopter with ease.Can be used for MJX F45 F46 / Giant QS8005 QS8006 / Wltoys V912 V913Align 450SE.Longth:33cm.Ball diameter:40mm.Color: Blue，Yellow(random)Please note that we don't offer color choice， all this item will be picked and packed at random.Specification:For Blade 400， Blade 450， Trex 450 and other similar helicopters Four training gear bars with balls installed at the end and held up by the fuel tubingPackage Included:4 x training gear bars with balls installed at the end and held up by the fuel tubing4 X Skid clippers2 X Center Hub