Aspects of the disclosure provide an amplifier. This is achieved by coupling the communications device to an adaptor which is configured to accept a Bluetooth connection from a Bluetooth enable device. A maximum torsion angle \u03b8 m is defined when the coil springs 58 are compressed to a maximum extent by relative rotation between the drive and driven members 52 and 53. In some cases, the universal receptacle cover is sized and shaped to completely cover standard electrical receptacles when the cap is in the closed configuration. The bipolar transistor also includes a base located above the emitter. A power tong is arranged for continuous rotation of an element connected to the pipe string, as the power tong is arranged in the fluid chamber.