[AA Battery Box 8881] Powers 2 L-motors or 4 M-motors simultaneously, requires 6 AA batteries (not included). [M Motor 8883 for High Speed] Provides strong power for high-speed and small-block motor applications. Supports forward and reverse operation. [2.4G Remote Control and Receiver] The motorized system features 4-channel selectors on the remote and control. They must be set to the same channel to function. The remote is powered by 3 AAA batteries (not included). [Compatible with Most Building Blocks] This set is designed to be compatible with most building block systems on the market. [Safety and Learning] Made from high-quality ABS plastic. Assembling blocks helps children develop hand-eye coordination, stimulate creativity, and enjoy the satisfaction of building. Material: ABS Plastic Color: Gray Package Contents: 2 * Medium Motors 1 * Battery Box 1 * Infrared Remote Control 1 * Receiver (Note: Light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3 cm.)