The FA-20H12.0000MD30Z-K3 is a MHz-range crystal unit designed for RF reference and clock applications across the 12 MHz to 54 MHz frequency range. This fundamental overtone crystal features a compact surface-mount package with external dimensions of 2.5 × 2.0 × 0.55 mm, making it suitable for space-constrained mobile and wireless applications. The unit offers frequency tolerance of ±10 × 10?6 for RF reference applications and ±30 × 10?6 for clock applications at +25°C, with operating temperature range from -40°C to +85°C (optionally +105°C). It supports load capacitance from 6 pF to infinity and features motional resistance (ESR) specifications ranging from 150 O maximum at 12–16 MHz down to 40 O maximum at 35–54 MHz. The crystal is ideal for mobile phones, Bluetooth, W-LAN, ISM band radio, and microprocessor clock applications, offering Pb-free and RoHS-compliant construction for environmentally responsible designs.