Aerial View Maps

Where can I buy a chain scale? I need a scale to measure chains on a 660 aerial map.?

A chain is 66 ft. My map is scaled 1" = 660' and i need a ruler style scale to measure chains. If anyone knows a good online place I would appreciate it.

Public Comments

1. Get a 1/10th scale. 1"=10 chains on that scale.
2. here's a link to them on ebay.