Hongfa RMTFL Series Relays. HongFa RMTFL series interface relay module featuring coil/contact separation and mechanical test button with flag indicator. The RMTFL modules are supplied complete with relay, socket, ejector clip and identification label providing a quick simple installation option. Features and Benefits. Supply status LED. Single or double pole options. AC and DC Coils. Test button and flag indicator. Changeover contacts. 35mm DIN Rail mounting