The PTC-F03 from NexTek, LLC. is a RF Surge Protector with Frequency DC to 3 GHz, Input Power 25 W, Insertion Loss 0.15 to 0.5 dB, Operating Current 3 A (Through), Operating Temperature -40 to 70 Degree C. Tags: Gas Discharge Tube. More details for PTC-F03 can be seen below.