Peltor optime 105 earmuffs, over-the-head, h10 ahv 3m peltor optime 105 hi-viz earmuffs, nrr 30 – twin cup design minimizes resonance, thus achieving maximum high and low frequency attenuation. Pivoting earcups for optimum fit. Padded steel headband with four point suspension for extra comfort. twin cup design minimizes resonance, thus achieving maximum high and low frequency attenuation. pivoting earcups for optimum fit. padded steel headband with four point suspension for extra comfort.