Used only once, Serial Number will come printed in the box with the device. The IK Multimedia ARC ON EAR Headphone Correction System is a high-quality audio accessory designed to improve the sound quality of headphones. The system, made by the reputable brand IK Multimedia, includes a unique on-ear design that enhances the audio experience. This product is ideal for musicians, DJs, and audio professionals looking to achieve a more accurate and natural sound when listening to music or working on recordings. With its innovative technology and sleek design, the IK Multimedia ARC ON EAR Headphone Correction System is a valuable addition to any audio setup.