Leviton's ST simplex adapters are available with metal housing and a precision zirconia ceramic split sleeve for providing low loss fiber connections over high and low-temperature extremes. These products are fully intermate able with all standard ST products and deliver very high stability under a wide range of applications and conditions. The 720 series utilizes. and high repeatability. What temperatures can the ST adapter be used in? The ST adapter can be used in temperatures as low as -40°C and up to 75°C. ST through‑adapters are the legacy workhorse of optical fibre networks.