This is a continuously variable transmission (CVT) made entirely out of LEGO pieces by Youtuber nico71240. Granted I have no clue what a continuously variable transmission is because I'm a stupid idiot, but I can tell it's impressive to build one out of LEGO.
This CVT enables a variation of the speed (and the torque) from 40rpm to 200 (1/5, 1,1) with constant speed for the motor (200rpm). This device is on the way to be included in a lego car. The two mechanical tachometers show respectively the speed of the motor and the speed of the output.
Cars, man, I don't GET them. You can yell at them all you want but that doesn't make them go. You have to like, feed them gas and stuff and sometimes they'll STILL just sit in your driveway and leak oil. *looking out window* DON'T YOU?! As soon as you're running again we're driving off a cliff.
Hit the jump for a video of the thing in action set to a song I could have done without.
Thanks to Alex, who told me to pour sugar in my gas tank because cars like sweets.