Renown’s BOP safe hi-flo gauge rings are designed to confirm casing integrity and spec.  These gauge rings are available in many sizes and are typically ran to drift of the well bore.  They are designed to prevent getting stuck in BOP profiles which can be very dangerous being so close to surface.  The gauge ring is ran on a channeled mandrel typically above your casing scraper.  This mandrel allows travel motion up and down to help work its way through impairments. Each gauge ring comes with large circulation ports to forward or reverse circulate debris past. Externally slotted gauge rings are available upon request.