The vibra-slap consists of a cowbell-shaped hollow box (acting as a resonator) and a wooden ball connected by a steel rod. The steel rod is bent in a an "L" shape that allows the performer to hold the rod in one hand and strike the ball with the palm of their other hand. The steel rod acts as a sort of spring that vibrates the box on the other end. The box acts as a resonating body for a metal mechanism placed inside with a number of loosely fastened pins or rivets that vibrate and rattle against the box, much like the teeth of the jawbone.
The sound is produced by small metal pins or rivets that can move on a metal frame and, when caused to vibrate (by shaking or striking), will rattle against the hollow box in which it resides, creating a chattering or rattling sound. The sound of the vibrations can be changed by rotating the box containing the pins.