Common Mast Model: A masts, K masts (open-front masts), derricks, masts and bootstrap masts. Jianxin Petroleum owns strong manufacturing capacity of steel ... .Product Features,Common Mast Model: A masts, K masts (open-front masts), derricks, masts and bootstrap masts.A-mast: its leg section is ... keep their stability and load capacity by guy rope.The bootstrap mast: the main body belongs to “K” section ...