Compare Quick view ANTHONY APOLLO ANTHONY APOLLO | POSI LOK RING - 17 1/2" OD | 27001-0054 MSRP: Was: Now: $272.37 ANTHONY APOLLO | POSI LOK RING - 17 1/2” OD | 27001-0054 STA-RITE SYSTEM 3, LOCK RING ..... DIMENSIONS OUTER DIAMETER: 17 1/2" INNER DIAMETER: 15 1/2" BUTTRESS THREAD ON THE INSIDE MARKED WITH LOCKED &... Add to Cart Add to Cart