The plantronics encorepro 540 is a quantum leap in convertible headset design its a 3 in 1 headset without compromise all of the wearing styles are designed with quality and comfort in mind in a system that is simple to convert but delivers a secure positive fit and finish the hw540 shares the advances of the other members of the new family with high quality audio a flexible mic with visual positioning guides soft ear cushions and durable yet lightweight materials for all day wearing