Over-the-Head Band 2.5mm Headset for Panasonic Office Home Cordless Phone System Designed for use with any cordless phone with a standard 2.5-millimeter jack; Boom-style microphone adjustable for optimum level Hearing protection technology, we are care about the users' hearing Microphone noise abatement can reach to the aviation noise reduction level Comfortable to wear: made of the flexible metal hose with the positioning accuracy MIC + Structural Design + Durable The Best Call Quality: Around 10,000 times Testing, the microphone boom rotates, 330 degree adjustable boom; Helical headphone cable which will avoid damaging during the use