This P-Series 8-pin lower-section hook-up cord is to be used with all J&M headset series #'s HS-ICD291, HS-BCD291, HS-ICD284, HS-BCD279, HS-ICD279, HS-CD9279, HS-BCD277, HS-ICD277, HS-BCD257, HS-BCD174, HS-ICD174 and #HS-CD9174 series helmet headsets, for connection to 1999-2019 J&M Corp® 6-pin audio systems.