100 Pack of Earbuds. Give students, members, guests or customers brand-new earbuds for personal audio use. Ideal for classrooms, schools, fitness centers, spas, gyms, educational use, hospitals, computer labs, hotels, motor coaches, libraries, training, trains, museums and more. 3.5 mm (1/8 inch) stereo plug works with iPods, iPhones, iPads, Chromebooks, Tablets, Computers, CD Players, Fitness and Audio Equipment. Speaker:10-15mm, Impedance :32Ω(Customized), Sensitivity :103dB±3dB at1000Hz, Frequency Range :20—20,000Hz. Plug:3.5mm stereo pin. Each Headphone individually packaged and sealed.