The ARG03FTC3900 is a high precision, low temperature coefficient of resistance (TCR) surface-mounted resistors (SMD) manufactured by Viking. It has a value of 390 ohms with a tolerance of 1%, a power rating of 1/10 Watt, and a size of 0603 RoHS. It is typically used in applications including various relays, amplifiers, and any other circuit components that require precise resistance values. Additionally, the ARG03FTC3900 is resistant to temperature cycling, shock, and vibration, making it suitable for a wide range of demanding applications.