The FC-13532.7680KA-AC3 is a kHz-range crystal unit manufactured by Seiko Epson for precision timing applications. It operates at a nominal frequency of 32.768 kHz with fundamental overtone order and is housed in a compact 3.2 × 1.5 × 0.9 mm package. The unit features a motional resistance (ESR) of 70 kO maximum, motional capacitance of 3.4 fF typical, and shunt capacitance of 1.0 pF typical, with selectable load capacitance options of 7 pF, 9 pF, or 12.5 pF. It operates reliably across a temperature range of -40°C to +85°C with a frequency tolerance of ±20 × 10?6 at +25°C and exhibits frequency aging of ±3 × 10?6 per year maximum. This crystal unit is ideal for small communications devices, real-time clocks, and portable electronics requiring stable, low-power timing references.