It sounds dirty, but it's really not. Fat Knobs are simply larger-than-normal knobs to put on the shift stick in your car. Call me immature, but I was laughing the entire time I was reading the page. It's full of sentences that are funny to people with really dirty minds, such as:
"The composite Fat Knobs weigh about as much as a billiard ball... The smooth finish feels great when you're working the transmission and the heft of the knob provides extra momentum for slamming gears."
"Fat Knobs come in black and white, but more colors may be available soon."
"Another thing we noticed is that in the heat of the summer sweaty palms can make the shifter knob a bit slick."
And the best one of the entire article: "The knob fits very well into the average person's hand and even my wife preferred the feel of the Fat Knob..."