An EMI collar is provided that is configured to be secured about a housing of a pluggable optical
transceiver module. The configuration of the EMI collar and the method by which the collar is attached to the housing of the
transceiver module ensures that the collar will not be damaged when the
transceiver module housing is inserted into a cage. Ensuring that the collar will not be damaged during
insertion ensures that
electrically conductive contact points on the collar will not be eliminated by
insertion of the housing into a cage. In addition, dimples, or indentations, formed on the spring fingers of the EMI collar result in additional
electrically conductive contact points on the fingers that result in a reduction in the size of the maximum EMI aperture dimension of the collar. Reducing the maximum EMI aperture dimension of the collar greatly improves the ability of the collar to attenuate EMI signals, even EMI signals having high frequencies.