The Male version of the female's thigh gap.
Dude, his ball window is so nice I can see them both!
Window typically found toward the front end of some older vehicles (classic VWs, Ford trucks), triangular in shape, directs large flow of wind into the vehicle and right up the leg of one's shorts, cooling their junk.
My old F-150's air conditioning went out, but my junk's cool thanks to the ball window.