Quartz Crystal also known as Quartz Crystal Oscillator. That was accomplished by means of "Piezoelectric" effect.
That is "Supply Voltage", Kingtronics common voltages are 1.8V, 3.3V, 5.0V.
The semiconductor devices and resistance capacitance element worked together, could constitute a Quartz Crystal Oscillator. 

Quartz Crystal Applications:
1, QKT-HC49U (HC-49U) suitable for electronic products with broad spaces such as communications equipment, televisions, telephones, electronic toys;
2, QKT-HC49U/S (HC-49U/S) is suitable for all kinds of space height restrictions thin and small electronic equipment and products;
3, QKT-HC49 SMD (HC-49U/S SMD) prevail surface mount products, applicable to all types of ultra-thin, small computers and electronic devices;
4, 3*8 Tuning fork Cylindrical quartz crystal resonators suitable for space-constrained timing frequency stabilization of electronic products such as timers, electronic clock, calculator, etc.

Kingtronics offers passive leaded quartz crystal HC49U, HC49S, SMD quartz crystal HC49SMD
and 3225 SMD Crystals. We also produce active 3225, 5032, 5070 SMD Oscillators.
We produce millions pieces of Quartz Crystal and SMD Oscillators monthly, the volume is keep increasing. Free samples for testing.
For more information, please visit: www.kingtronics.com/quartz-crystals/