Pavement Adjustment Rings - JR Hoe & SonsAdjustment. Rings? Two Kentucky Locations: Louisville. 502-326-1347. 502-326-1386 fax. Middlesboro. 800-245-5521. 606-248-6308 fax salesjrhoe.zenith hp700 adjustment ring for sale,Manholes - Storm Manholes - Manhole Adjustment Rings and .Manholes. The Manhole is a belowground round or square struction made of precast concrete. At street level, an iron access cover (manhole cover), is placed to.