Pneumatic drills, also known as air powered drills, are mechanical drills that run on compressed air. Instead of using a battery, they require a hose connected to an air compressor. They perform the same functions as an electric cordless drill driver or a corded drill, but they weigh less and perform without the use of electricity or charged batteries, making them favored by plumbers and construction workers. They are often used to drill holes in rock and construction. Compared to electric drills, they cost less to operate and maintain, and they have a more ergonomic design. They are more versatile and can be used in more situations than electric drills. Many have throttles for variable speeds, which makes it easy to start holes and get max torque.