Initially I was very pleased with this device: (a) Simplicity of physical installation (b) ease of configuration and use with our three phones and (c) sound quality on both ends of each called we tested. However, the device will be sent back because after less than 10 extend/retract sequences of the spring-loaded pop-out mic, it stopped locking upon retracting. As a result of the mic being stuck in the extended position, the unit is always powered on.