This corrosion-resistant epoxy-coated marker with durable brass screwcap is designed for accurately establishing a vertical datum line without the need for a level. Ideal for surveyors, engineers, and construction professionals, it provides a stable and long-lasting reference point in a wide range of environments. The robust epoxy coating protects against moisture, chemicals, and general wear, ensuring reliable performance over time. The precision brass screwcap allows easy access and secure closure, helping maintain calibration integrity. Suitable for indoor or outdoor use in commercial, industrial, or infrastructure projects where consistent vertical alignment and dependable datum control are essential.