The Proto X from Estes claims to be the world’s smallest quadcopter and also one of the world’s lightest. The 1.8″ x 1.8″ Proto X is tiny, ideal for indoor flying — and it weighs only four-tenths of an ounce.Bright, built-in LEDs make it easy to see the Proto X in low-light conditions. A 2.4GHz radio not only allows for interference-free flight — it makes it easy for multiple Proto X helis to fly at once. A 3.7V 100mAh LiPo battery, USB charge cord and spare rotor blades are also included in the ready-to-fly package. It is sold without the two “AAA” batteries needed, for $39.99.