Precision Metal Film Fixed Resistors - R Series (10Ω - 249Ω) TE Connectivity R series precision metal film resistors with a tolerance of 0.1% and a temperature coefficient of 15ppm. The R series precision metal film resistors have outstanding stability under load and severe environmental conditions, making them ideally suited for applications where long term stability is imperative. As part of the manufacturing process of the R series precision fixed resistor, all are tested for value and tolerance.