Yonex Mavis 600 Badminton Shuttles. When smashed, a MAVIS shuttlecock recovers in only 0.02 seconds. This performance is just 0.005 seconds slower than a YONEX Feather shuttlecock and 0.008 seconds faster than the recovery of an ordinary shuttlecock. Players should always use the shuttlecocks best suited to the playing environment. The hardness of the skirt - the feather part of the nylon shuttlecock - varies depending on temperature. In the cold, as the skirt becomes hard, it is prone to breaking. In the hot, the skirt becomes softer and less likely to break, but the feel at impact is affected by the softer skirt. YONEX manages product quality by categorising MAVIs into temperatures; Fast (Red Cap) for 0- 13 degrees Celsius. Medium (Blue Cap) for 12 - 23 degrees Celsius Please ensure that you choose the shuttlecock best suited to the playing environment. Developed using the flight timing of feather shuttlecocks, MAVIS Nylon shuttlecocks are precision designed and manufactured to provide accurate flight performance. The WING RIB design utilizes air flow through the shuttlecock to restore shape quickly on impact. Based on flight dynamics, this original design grants stable flight, contrary to conventional models that restore shape via stiff construction. Shuttlecocks should be stored away from high temperatures and the tube kept upright with the cork side of the shuttlecock facing down. Each tube contains 6 shuttles.