Thank you for all the inquiries! Serial # 5946 K3/100-F 100 Watt KAT3-F K3 ATU KFL3A 2.8 Khz Filter Swap KFL3A 400 Hz Filter Power cable Anderson Poles on both ends Owner’s Manual, plus Fred Cady – KE7X “The Elecraft K3 – Design, Configuration, and Operation Manual” 73 de Jim - KE8G