The earphones are optimally designed to provide high-sensitivity, low-distortion and a wide, smooth frequency response.Perfect for province, city CDC,city physical examination center, ENT department in hospital, deaf training school,driving school,hearing clinic,hearing aid speciality store, etc. Why not have a look? Features: It's intelligently and ergonomically designed, easy to use. The earphones are optimally designed to provide high-sensitivity, low-distortion and a wide, smooth frequency response. Suitable for all imported audiometer, providing high-sensitivity. Perfect for province, city CDC,city physical examination center, ENT department in hospital, deaf training school,driving school,hearing clinic,hearing aid speciality store, etc. Hands-off screening gives the operator complete control of testing procedure. With microprocessor control, result in accurate, consistent hearing tests. Unique instrument advances pure tone air conduction threshold and screening tests for hearing. Specification: Item Type: Headphone for Audiometer Material: Plastic + Composite Cloth + Alloy Plug Type: AIPUTE DC:10 Ohm 1.0 Ohm Power: 100-8000Hz Input/Output: 1000 mW Plug Diameter: 6.5mm /0.25inch Earmuffs Diamater: 7cm /2.75inch Sensitivity: 3dB Distortion Rate: 3% Color: Black Frequency: 125-8000HZ Package Weight: 516g/18.2oz Function: Use for audiometer air conduction testing and screening Package List: 1 x Headphone 1 x User Manual