L293D is a monolithic integrated, high voltage, high current, 4-channel driver,you can use DC motors and power supplies of up to 36 Volts, the L293D chip is also known as a type of H-Bridge,which is typically an electrical circuit that enables a voltage to be applied across a load in either direction to an output, e.g. motor.

2 interface for 5V Servo connected to the FOR Arduino 's high-resolution dedicated timer - no jitter.
Can drive 4 DC motors or 2 stepper motors or 2 Servo.
Up to 4 bi-directional DC motors with individual 8-bit speed selection.
Up to 2 stepper motors (unipolar or bipolar) with single coil, double coil or interleaved stepping.
4 H-Bridges: per bridge provides 0.6A (1.2A peak current) with thermal protection, can run motors on 4.5V to 36V DC.
Pull down resistors keep motors disabled during power-up.
2 external terminal power interface, for seperate logic/motor supplies.

Reset button
Size:70*55mm

Compatible with : Arduino Mega, Diecimila & Duemilanove.