wet-o-wheel detector

Wet-O-Wheel Detector ~or~ WOW Detector:
Fictitious measuring device or instrument referenced when determining the level of sexual excitement & arousal in a woman. Commonly used in speech amongst females as a barometer to score or articulate the level of attractiveness of a man.

"What do you think of Michael?"
"He measures an 8.5 on my Wet-O-Wheel Detector"
"Yeah, well I've seen Micky naked; he's a 10 on the WOW-D"