Key Specifications / Parameters Specification Detail Part Number 18A0824X012 Product Type Bushing / liner for bellows‑seal bonnet Stem Diameter Fitment 12.7 mm (½‑inch) Compatible Bonnet Type ENVIRO‑SEAL bellows‑seal bonnet style Material/Construction Stainless steel (S31600) with PTFE lining Intended Function Guide the stem and maintain sealing in the bonnet assembly under elevated or vacuum service conditions