586 lengths of 4 1/2″ 16.6 lbs/ft S135 400 DUO range 2 drill pipe and 100 lengths of 4 1/2″ 400 DUO heavyweight were inspected with 12 ends (<1%) needing machine shop repairs. This remains consistent with past inspection results on all sizes of the DUO connection family currently being used. Follow the link below to our DUO brochure and DUO highlights.