H31: StarSet® Headset An excellent choice for applications demanding top-notch acoustic quality and all-day comfort. Soft Versatip® eartip for custom fit and acoustic seal Comfortable, over-the-ear design (can be worn on either ear) Ultra-lightweight (less than .5 ounces/14.2 grams) Supports Soundguard Plus and Call Clarity technologies for superior sound Quick Disconnect™ option and an adjustable clothing clip Clear adjustable voice tube Amplifier/Adapter Required: M12 Vista Telephone Headset Amplifier A20 Telephone Headset Amplifier CA10 Cordless Telephone Headset Amplifier