We manufacture the quartz crystals from the very beginning of 2000,then established the JJK Company in 2004,many years of producing experiment and technology make our company to be the professional and largest suppliers of quartz crystals in China. Our products used in the film thickness deposition control ,are available to most thin film monitor applications,film thickness controllers, such as MDC360,QCM310,SQC310 XTC-3/-5 and so on.