Precise map measuring tool: Clear graduation marks and beveled edges provide accurate distance measurements on maps and charts for students, cartographers, and outdoor users. Transparent plastic construction: See the map beneath the ruler while plotting coordinates or tracing routes, improving placement accuracy and reducing parallax error. Dual-function scale: Measures both width and length, making it suitable for scaling map distances and transferring measurements between charts. Two size options: Available in 37 cm or 47 cm to match different map sizes and working areas—choose the length that fits your mapping needs. Simple, reliable performance: Straight edges and clear markings make repeated measurements fast and consistent without special setup or calibration. Typical uses Students and educators: Quickly measure map distances and teach map-reading or scale conversion in classroom exercises. Cartographers and GIS users: Plot coordinates, transfer linear measurements, and check scaled distances on printed maps. Outdoor navigation: Plan hiking routes, estimate travel distances, or use alongside nautical charts when navigating at sea. Key attributes Function: Accurate distance measurement and coordinate plotting on maps Compatibility: Works with printed maps, charts, and paper-based plotting Size choices: 37 cm or 47 cm Material: Transparent plastic Performance: Clear markings and beveled edges for precise, repeatable measurements