Sino Science & Technology Co., Ltd. is a professional designer and manufacturer of optical instruments: refractometer, microscopes and the instruments for gem testing and lab use. We provide many series of refractometers both of traditional and digital and
a varity of gemological instruments such as gemological refractometer, spectroscope, polariscope, dichroscope, chelsea filter, gem magnifier and gem Gauge with favorable prices. Apart from that, we are also manufacturer of scientific instruments with high precision for your service, such as borescope, PH meter and polarimeter thermometer.