Mute Mode - Licence Key (SKU: HKVN4498A) Licence Key for the Mute Mode feature. This key activates the Mute Mode in DP2x00/e, DP3xx1/e, DP4x0x/e, DP4x0x Ex, DP4x0x Ex Ma, SLx600, SL40x0/e, DM2000, and DM4x0x/e series radios. Mute Mode provides a quick...