1-Bit quality used bit but good quality 2-API or ISO 9001:2008 3-Bit Price:USD98- ... well, oil field, construction, geothermal, directional boring, and underground foundation work Formation sticky, soft, medium hard, hard formation Bearing rubber seal ... Piece Supply Ability 1000 Pieces/month Delivery Time within 7 work days SizeBit TypeIn.mm6152.4517G, 537G, 617G, 637G6 1/2165 ...