For these products:
ACS: SSA amplifier (This is the only ACS amplifier that requires the 8800-01 cord)
Avaya: 4600 IP Series
Mitel: 4000 and 5000 IP Series
Plantronics: PLX-400, PLX 500, Practica, A100 S10, SOH 1858-12, SP-02, SP-04, SP-05, T10, T20 and other applications
Use any of these GN Netcom Headsets (These headsets require an amplifier): GN 2110 ST, GN 2115 ST, GN 2117 ST, GN 2120 NC, GN 2125 NC, GN 2127 NC