.L293D motor drive shield expansion board is a commonly used DC motor drive module, using 293D chip small current DC motor driver chip. The pins are made compatible, which also facilitates the quick for some based development for enthusiasts. L293D is a monolithic integrated, high voltage, high current, 4-channel driver.Basically this means using this chip you can use DC motors and power supplies of up to 12 Volts, thats some pretty big motors and the chip can supply a maximum current of 600mA per channel. 4 H-Bridges: per bridge provides 0.6A (1.2A peak current) with thermal protection, can run motors on 4.5V to 12V DC 2 interface for 5V Servo connected for high-resolution dedicated timer - no jitter. Tested compatible for Mega, Diecimila & Duemilanove.