The newly developed Perfex KT-20 four-channel 2.4 GHz R/C system features a large LCD that displays battery voltage, digital trim positions, or control mode. The radio also features a built-in charger for the included Li-Po battery that powers the plane. Up to 25 Minium aircraft can be flown at the same time, and up to three aircraft can be linked to the same transmitter, which is also compatible with the new Caliber 120 micro heli. That means you can purchase a ready-to-fly airframe (Minium AD or Caliber 120) that's available without a transmitter to save the extra expense. Simply install four AA-size batteries in the transmitter and you have everything you need for an afternoon of flying. The Minium AD has a wingspan of just 16 inches (410mm). With a high-power motor delivering 10% more power and a newly designed propeller as standard, this model can be flown outdoors (with light winds) as well as inside. And it is fully pre-assembled and fitted with an ultra-small control unit with built-in ESC, receiver, 3 servos, and pre-set linkages.