30 Packs Headphones with 10 colors,each Bulk Headphones Individually Sealed Designed with Adjustable headband, comfort and lightness,ideal for classroom use and school testing Provide you with stereo audio clarity and nice sound quality colorful headphones Stereo 3.5 MM Plug and 4ft Cord Works with Smartphones, Chromebooks, Tablets, Laptops, Computers, Fitness and Audio Equipment These headphones can be widely applied for classrooms, school, libraries, museums, hotels, gyms and more places