The a10 cable can be used with any h series headset to connect directly into a phones headset port when the a10 cable is used no other amplifier is required easily connect any plantronics h series headset to a headset ready phone via the headset port with a10 recommended for use in an environment with a mix of m22 amplifiers and direct connect solutions allows h tops to be used in amplified and direct connect systems ndash and reduces the risk that the wrong headset will be connected