Suntsu Frequency Control, Inc. is an ISO 9001:2008 certified supplier of quartz crystals, crystal oscillators, oven controlled crystal oscillators (OCXOs), temperature compensated crystal oscillators (TCXO......Suntsu Frequency Control, Inc. is an ISO 9001:2008 certified supplier of quartz crystals, crystal oscillators, oven controlled crystal oscillators (OCXOs), temperature compensated crystal oscillators (TCXOs), voltage controlled crystal oscillators (VCXOs), and precision time modules. Our ambition is to supply cutting edge frequency control products through recognition and development of the latest technological advancements. We encourage creativity and support industry innovation by designing and manufacturing custom components specific to your applications.