multiple capacitor

Above figure shows that multiple capacitor which is a parallel combination of several parallel plate capacitors and is of fixed capacitance. Mica is used as dielectric which has dielectric constant 6 between a number of tin foils arranged in parallel.
If the capacitance between two successive plates is C, then the capacitance of the multiple capacitor is nC, where n is the number of dielectric plates used. This whole arrangement is sealed in a plastic case. These capacitors are used in high frequency oscillating circuits. Since, mica's dielectric constant does not change with temperature, so these capacitors are used as standard capacitors in the laboratory.