The ZE300 is a newly designed model based on the brand's ultra-compact housing of the "COTSUBU series", of which over 500,000 units have been produced to date. It is the smallest and lightest noise-cancelling earphone, and its size is approximately 20% smaller than the ZE3000SV, making it ideal for those with small ears, as it prevents the earphone from protruding. The internal mechanism has also been completely redesigned to fundamentally improve sound quality and comfort.