Built to Last with Polycarbonate. ATC navigational aids are crafted from durable, lightweight polycarbonate, offering exceptional strength and impact resistance. The material is crack and warp-resistant, ensuring long-lasting precision. Its clarity aids in accurate measurements, and with UV resistance, these tools perform reliably in various conditions. Scales: 1:1,000,000 Nautical Miles (For WAC Charts) 1:500,000 Nautical Miles (For VNC Charts) 1:250,000 Nautical Miles (For VTC Charts) Clear polycarbonate plastic, supplied with plastic protective sleeve. Additional information: Weight: 0.02 Kgs Dimensions: 16 x 5.5 x 0.1 cm Other Available Versions: Aviation Theory Centre ATC Scale Rule 180NM $22.00 Aviation Theory Centre ATC Scale Rule 120NM $17.50