This replacement jack is used on the master station and remote headset station. It allows the headset to connect to the master station and/or the remote headset station by inserting the appropriate plug. This part is compatible with the following ground support communication system models from David Clark Company: C35-08, C35-16, C35-26, C35-30, U3410, U3800, U3801, U3802, U3806, U3811, U3814, U3815, U3815A, U3816 . Integrates with the Neoprene Washer and Jack Cover with Nut.