The first super-lightweight communications headset was introduced by Plantronics in 1962. Today, Plantronics is the world leader in the design, manufacture and marketing of super-lightweight communications headset products. Plantronics offers a comprehensive range of products for a variety of areas: headsets for mobile needs, i.e. headsets for cordless phones and mobile phones, computer audio headset products for the next generation of computer applications, conventional and cordless headsets and systems for enterprise, telecommunications/home office and call center. This adapter is intended for use with Merlin 4406D+, 4412D+, 4424D+, 4424LD+ and Definity 6416, 6424D+M telephones.