Corded concrete vibrators remove air pockets from newly poured concrete to ensure that it consolidates and reaches its maximum finished strength. They prevent honeycombing (bug holes) and properly pack the aggregate to increase density and reduce rework and surface patching. Also known as immersion vibrators, their rod-shaped head inserts into wet concrete and pulsates to force air bubbles up and out at the surface. They emit a radius of vibration that is four times the head width to vibrate concrete in sections.