LED Clothing Sound Activated Tie for Birthdays, EDM, Festivals, Halloween Party SOUND ACTIVATED - LED lights pulse to the beat of the music with varying levels of intensity. The built in sensor detects sound waves and will display 4 different levels of vibrant light. The louder the music the more lights are activated! When the beat d ADJUSTABLE SENSITIVITY  A dial on the side lets you raise or lower how sensitive the LED lights are when they sense music. LED Tie length - 19 inches with an adjustable 24 inches neck clip. Takes 2 AAA batteries (not included). Battery compartment is hidden away at the bottom of the LED tie.