Key Features Fully assembled, no building necessary SAFE technology makes helicopter flight more fun Panic recovery mode can prevent a crash Fly barless rotor mechanical simplicity Durable construction with carbon-fiber components High-speed coreless main and tail rotor motors (installed)Sub-micro linear long-throw cyclic servos (installed)E-flite 500mAh 1S 3.7V 25C Li-Po flight battery and charger (included)Needed To Complete Multifunction 6+ channel transmitter with Spektrum DSMX 2.4GHz technology. Overview The original Blade 120 SR heli was specifically designed to provide the inherent stability of a coaxial helicopter and the agile control of a single-rotor helicopter. Modeled after the popular ultra micro-size Blade mgr. heli, the larger 120 SR heli was faster and more powerful so it could be flown outdoors. Now that concept takes a leap forward with simpler mechanics and the superiority of SAFE technology so that pilots master the basics of single-rotor flight more easily. The sub-micro Blade 120 S is a great way to graduate from coaxial helis and multicolor drones to a single-rotor machine. Fixed-pitch, rotor mechanical simplicity lets you enjoy extra speed and agility with a design that has a high-level of durability and efficiency. Exclusive SAFE technology helps keep you in control by delivering the stability you need to develop confidence quickly. Move up to higher levels of flight performance easily with the flip of a transmitter switch. Prevent a crash the second you feel disoriented—just press the Panic Recovery button and SAFE technology locks the 120 S into a familiar level attitude. So whether you aim to advance your skills, or want a fun fly-around heli, the Blade 120 S can help you be the master of single-rotor flight.