Audio-Technica ATH-ANC23 QuietPoint Active Noise-Cancelling In-Ear Headphones

Reduce distracting background noise by up to 90% while offering superior sound.
Engineered to create a comfortable listening environment in areas with high ambient noise.
Feature a miniature microphone in each earpiece that picks up ambient noise.
Electronics in control box create a noise-cancelling wave that is 180 out of phase with ambient noise-wave acts as noise eraser.

Used, good condition.