The ZTW Beatles series of speed controllers is an entry level product line for fixed-wing aircraft This series is specially designed for the price-sensitive beginner who requires a straightforward solution thats ready to use right out of the box (no programming is necessary), yet still demands quality and performance. That said, if you wish to program your ESC you can use the air program card (sold separately). The Beatles series, then, are light in weight, small in size, offer super smooth start-up and throttle linearity, multiple protection, and all at incredibly competitive prices.