The Wilkins 475STDA and 475STDAV are reduced pressure detector assemblies (RPDA). The 475ST comes in the “N” configuration. The 475STV comes in the vertical “Z” configuration. Production started in 2017 and is current They are available in 4″-10″ sizes. Their bodies are made of stainless steel. The 475STDA and 475STDAV utilize a 3/4″ 975XLD for the bypass device.