SD Office is a single-sided premium DECT wireless headset for desk phone and softphone. It features 2-in-1 wearing style, Sennheiser HD sound and voice clarity, noise-canceling microphone and ActiveGard. With Sennheiser HD sound and voice clarity for you and your listener - the conversation is always clear. Sennheiser ActiveGard technology protects your hearing against acoustic shock. Enjoy your calls in HD voice clarity and get natural high-definition sound for superior voice clarity. Work safely ensured that the ActiveGard technology will protect your hearing.