Shenzhen Sthanco Technology Co., Ltd. is a high-tech company engaged in electronic security and optical communication industry, integrating R&D, production and sales. We specialize in producing HDMI/VGA/DVI extenders, HD / 3G-SDI / HDMI / VGA fiber converters, HD-CVI / TVI / AHD video converters, FXS / FXO telephone voice fiber converters, audio RCA broadcast fiber converters and RS485 / 422 / 232 serial fiber converters. All of these products are widely used in banking, electricity, transportation, coal mines, schools, border defense, shopping malls and communities.