17-3/4" main rotor diameter, 16-1/2" long, 9-7/8" tall, 14-1/2 oz. flying weight. Almost 25% larger than the Co-Co Lama, with greater stability. The larger size makes the MD500 easier to fly, either indoors or outdoors. The helicopter is able to withstand a bit more wind and is capable of forward flight, which is good for learning the skills necessary to move up to a collective pitch helicopter. Powered with two 370 series brushed motors, the helicopter has plenty of power. The 2 cell lipo battery will give you approximately 10 minutes of flight time. Everything that is required (less the 8-AA transmitter batteries) is included. Since there is no assembly, all you need to do is charge the flight battery with the included lithium safety charger, install 8-AA cells in the 4-channel 72 MHz transmitter, and you are ready to fly. MD-500 includes extensive use of ball link connections for superior control. Includes spare set of main rotor blades (Note from Dave: I don't have a full set of spare blades for these). The mixing board with gyro and speed controls is separate from the 6-channel 72 MHz radio receiver. This gives you the option of changing radios with no additional modifications, or using the radio and receiver in a future project. The flight battery compartment is easily accessed and changing the flight battery takes only a few seconds. Durable, easy to fly, and ready built.