DESC: The Panasonic KX-TAC90 convertible telephone headset is sleek and comfortably designed for long, hands-free conversations. It can be used with any headset-compatible cordless or cellular phone that has a 2.5-millimeter jack.The KX-TAC90 features a slim headband, a padded earpiece and headpiece, and a fully adjustable microphone. In our tests, the headset was extremely versatile and required little assembly. The microphone can ostensibly be worn with the headband on either ear or it can be hung from the ear using the included large and small ear attachments. However, in our tests, the microphone did not stay in place well unless worn with the headband.The sound quality of the earpiece and microphone were both clear. The headband was light and sturdy as well, making it comfortable to wear for long periods of time. The KX-TAC90 has a noise-canceling microphone that eliminates background noise and makes your voice more easily understandable to callers. It also has a 4-foot cord with an adjustable clothing cli