A feedback architecture for a PWM switching audio amplifier is, capable of compensating the effects of the demodulation filter through at least two feedback paths of the voltage applied to a load without degrading the overall loop gain of the device. The compounds of the invention possess similar or superior LPO inhibition activity to the reference compounds of Trolox and Ebselen. Moreover, this module and software system includes the capability of providing secure POS transactions to legacy transaction processing systems transparently to the existing infrastructure. The method presents at least one viewing area on the portable device display to be viewed by the local participant, and changes the at least one viewing area to be presented on the portable device display based on cues provided by the operator. There would then be provided a reinforcement ring at each point where a pair of legs of lifting loops are stitched to strengthen the attachment point.