Silver mica capacitors are high precision, stable and reliable capacitors. They are mostly used at high frequencies and in cases where low losses (high Q) and low capacitance change over the time is desired. Circuit designers still turn to silver mica capacitors for high-power applications such as RF transmitters, instruments and amplifiers because cheaper ceramic and porcelain capacitors can't withstand heat and degrade over time. Silver mica caps are also widely used in high-voltage applications due to mica’s high breakdown voltage.