The HC-49/U-S4000000ABKB is a high-quality 4MHz quartz crystal manufactured by Citizen. Supreme Components International is an authorised distributor of Citizen electronic components, ensuring you receive genuine products. This crystal is designed for applications requiring precise and stable frequency control. The HC-49/U package offers robust performance and easy integration into various circuit designs. It is commonly used in microcontrollers, communication equipment, real-time clocks, and other timing-critical applications. Its compact size and reliable performance make it a versatile choice for both prototyping and mass production. Trust Supreme Components International for your Citizen component needs.