The AB308-4.000MHZ is a high-frequency cylindrical microprocessor crystal designed for precision timing applications in consumer electronics and computer peripherals. This miniature crystal operates at a fundamental frequency of 4.000 MHz with tight vacuum sealing to ensure high stability and reliability. It features an equivalent series resistance of 150 O at the 4.000–5.999 MHz range, a shunt capacitance of 5 pF maximum, and a typical load capacitance of 16 pF, with frequency tolerance of ±30 ppm at +25°C and frequency stability of ±50 ppm over the operating temperature range of -10°C to +60°C. The crystal is housed in a compact 8.0 × Ø3.0 mm cylindrical package and is suitable for microprocessor clocks, test equipment, and various consumer electronics applications requiring stable frequency references.