Paddle shifters are levers attached to the steering wheel or column that allow drivers to manually shift the gears of an automatic transmission with their thumbs.
Many automatic transmissions come with manual shift capability that is engaged by first moving the console-mounted shift lever to a manual mode. The driver can then use the steering-wheel paddles to shift gears up or down manually instead of letting the transmission do the work automatically.
The paddles are typically mounted on both sides of the steering wheel, and one (usually the right) controls upshifts and the other downshifts, and they shift one gear at a time.