The RCA series utilizes technology that is similar to standard thick film series, but there is a significant difference in the design of its inner termination. A standard thick film SMD resistor has pure silver inner termination while the RCA series has an additional layer of protection to safeguard exposure to high content sulfur environments. The increased inner termination protection ensures the RCA series is sulfur resistant in accordance with ASTM B809-95 standard and EIA-977 standard.