Features: Experience precise marine navigation with the Marine Navigation Parallel Ruler, featuring solid arm for durability. This 17inch parallel ruler ensuring stability and accuracy in measuring distances and angles on Chart. For professional, captains, enthusiasts, and maritimes students seek reliable navigation tool. Perfectly suited for chart plotting, route planning, and maritimes navigation training, this tool is essential for any serious seafarer. Enhances your navigational skills with this expertly crafted instrument, to withstands the rigor of sea voyages while providing clear scale marking for easy use. Specifications: Material: ABS Total Length: About. 450mm/17.72in Package Includes: 1pc Marine Navigation Parallel Ruler note: Please allow 1-2cm errors due to manual measurement. Due to difference between different monitors, the picture may not reflect the item actual color.