Check the listing for details. Nap Zapper: Ear-Mounted Drowsiness Alarm for Drivers & Workers. Condition: New. Listed at 4.99 USD. The Nap Zapper is a simple device that could just save your life- or help you keep your job! The small, flexible device rests comfortably over the top of your ear and will sound an alarm to wake you if you start to doze and your head nods forward. Perfect for sleepy drivers or someone working the late shift. It works great for security guards, machine operators, and even students struggling to stay awake while studying.Features:Design: small and lightweight (approximately the size of an external hearing aid)Flexible rubber comfortably rests over the top of your ear3 Functions: Switch from the audible alarm function, to vibrate for crowded settings, to off when not in useDimensions: 2 ¾ x 2 x ½ inchesWarranty: 1 yearContents:Streetwise Nap ZapperThree LR41 Batteries