Closed Retort Ring made from plated mild steel Inner diameter of ring measures 2" Stem measures 5.5" in length Rod diameter measure 0.25" Total Length measures 8.1" Eisco Labs 2.5" Stainless steel Retort Ring Closed with 6.5" stem, 0.25" diameter rod, Inside Diameter of ring 2" - Total Length is 9.125"