A nickel based alloy coating and a method for applying the nickel based alloy as a coating to a substrate. The macro cell may be connected to the RRHs, for example, by optical fiber, and there may be negligible latency between the macro cell and the RRHs. Subsequent depression of plunger handle in the direction of arrow A causes safety bobbin to move along barrel, from which position it can not be withdrawn. A tag associated with the element is selected.