A delay circuit for delaying an input signal with a desired delay and outputting the delayed signal. The holder unit has a first spacer and a second spacer. The linking uses an identifier that does not include any personally identifiable information. The multiplier adder is a function of an average of desired fueling data taken over a time interval that includes engine cranking, starting, and initial engine running. To provide accurate operation, the transmitter transmitting the electromagnetic signal is a transmitter part of a heart rate monitor or a heart rate measuring system. The first region may include the second region.