Rainproof Mechanical Map Distance Wheel

A purely mechanical map measuring tool with precision-machined metal wheel and direct-read metric counter; overall size approx. 8 cm x 8 cm x 3 cm; total weight less than 120 g; body combines anodised aluminium wheel axle, stainless steel gear train, and UV-stabilised ABS plastic casing; fully sealed against light rain and splashes; measures distances from 0–999 m per revolution with clear, non-fogging dial display. Designed for tactile, intuitive operation: roll the wheel steadily along any map line — whether straight road segments or serpentine river courses — and read real-time accumulated distance without setup, pairing, or software. The low-friction wheel maintains consistent contact on glossy OS maps, matte trail pamphlets, or folded laminated guides. Used by UK Mountain Training instructors, Duke of Edinburgh leaders, and long-distance walkers preparing for Pennine Way or GR routes — especially where phone battery conservation and offline redundancy are critical.