RC55 Precision Metal Film Resistors Welwyn / TT Electronics RC55 Precision Metal Film Resistors are CECC-released devices with low TCRs over a wide resistance range. Welwyn / TT Electronics RC55 resistors feature a resistance tolerance down to 0.05%, low noise, negligible voltage coefficient, and screened parts available for critical applications. The resistors are offered in a resistance range of 1RΩ to 4MΩ with a 0.25W power rating at +70°C, 350V limiting element voltage, and a 500V isolation voltage.