Wl Products - 4CH 2.4GHz Mini Radio Single Propeller RC Helicopter Gyro V911 RTF Red and Black - This 4CH 2.4GHz mini RC helicopter with pioneering single propeller, built-in Gyro, extremely light weight, strong resistance of impact, steady and agil New and high quality Can fly outdoor in the wind weather(out door wind grade 3-4) Suitable for children of 15 years old&up With 2.4GHz radio system, many helicopters can fly at the same time without interference.