耳机延长线的作用是针对原配的耳机线不满足使用要求，对其插头进行对接延长，主要有直线型和Y型两种延长类型。

C31-XX Series Extension Cords

• C31-12 - 12 foot, Straight Cord with (SC-838) Female Connector and (PJ-051) Plug
• C31-25 - 25 foot, Straight Cord with (SC-838) Female Connector and (PJ-051) Plug
• C31-50 - 50 foot, Straight Cord with (SC-838) Female Connector and (PJ-051) Plug
• C31-100 - 100 foot, Straight Cord with (SC-838) Female Connector and (PJ-051) Plug

C31-26 - 26 foot(extended), Coil Cord with (SC-838) Female Connector and (PJ-051) Plug

 P/N 18253G-12 - 12 inches, Straight Cord with (SC-838) Female Connector and (U174/U) Plug

High visibility "DAY-GLO ORANGE" Extension Cords enhance safety during Airline/Airport Ground Support, Push-Back and Ramp Maintenance Operations. Designed for use with any David Clark Series 3000 Ground Support Headsets. Available in two lengths:

• C31-15DG (P/N 18874G-05) - 15 foot (extended), Coil Cord with (6J-1176) Jack and (PJ-051) Plug
• C31-26DG (P/N 18874G-06) - 26 foot (extended), Coil Cord with (6J-1176) Jack and (PJ-051) Plug

Y Adapter Cords

A "Y" Cord Adapter is required to connect any David Clark Series 3000 Noise Attenuating Headset to an aircraft that is equipped with two external jacks for access to the aircraft's intercom system. This addition makes the Series 3000 Headsets more versatile.

P/N 18253G-10 - 23 inches, Straight Cord with (SC-838) Female Connector (PJ-055) Plug and (PJ-068) Plug

P/N 18253G-11 - 26 foot, Coil Cord with (SC-838) Female Connector and (PJ-055) Plug and (PJ-068) Plug

P/N 18253G-15 - 23 inch, Straight Cord with (PJ-051) Plug and 2 (SC-838) Female Connectors. Great for training applications.