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. Spec:Item Type: Headphone for AudiometerMaterial: Plastic + Composite Cloth + Alloy Plug Type: AIPUTEDC:10 Ohm ±1.0 OhmPower: 100-8000HzInput/Output: 1000 mWPlug Diameter: Approx. 6.5mm /0.25inchSize: Approx. 20.5 x 10cm / 8.1 x 3.9inchSensitivity: 3dBDistortion Rate: 3%Color: GrayFrequency: 125-8000HZPackage Weight: 516g/18.2ozFunction: Use for audiometer air conduction testing and screeningPackage List:1 * Headphone