Embodiments of golf club heads and methods to manufacture golf club heads are generally described herein. The combustor is for a gas powered turbine which employs the hypergolic or high energy air stream which will allow a fuel to be combusted in the absence of an additional ignition source. Furthermore, an element is described for adapting a danger sensor to different requirements regarding the power supply; also described is an arrangement for detecting of a danger situation and a method for retrofitting of the power supply to a danger sensor. The first and second rubber grommets have chamfered ends to facilitate push-in insertion into the apertures, and the first and second rubber grommets each have a central opening to receive headed attachment rods therein. The receiving device then receives an indicator to change encryption algorithms.