Jrelecs K-BAR 5.3.4PRO V2 3-Axis Gyro System for Flybarless FBL 450 500 550 600 700 RC Helicopter-Gold Application: For ALIGN (Or other Brands) T-REX 450 SE/V2, Sport, PRO/PRO V2 , 500 550 600 700 rc helicopter Shell material: durable hard plastic. Size(L*W*H) : 30 x 38x 13mm. Programming Assistant (Setup Wizard):  gets you ready for flight in 11 steps. Fine adjustments can be done at the field in your transmitter (no PC necessary). Added Functions: 1. Four sides installation available, total 8 installation method. 2.With LED indicator lamp 3. Offer Gold color enclosure K-BAR 5.3.4PRO V2 3-Axis Gyro System Gold. Easy Start setup via PC or Control Panel.