This transparent plastic scale is designed for use on USGS 7.5 and 15 minute series maps. Scales for 15 minute series: 1:62,000 or 1"=1 mile; 7.5 minute series: 1:24,000 or 1"=2000'. 15 minute scales are printed in red and 7.5 minute are printed in black. 4-1/2"H x 6"W.