Write and Wipe Charts are white, screened in black with bold black X-Y axes, and with plain back. The charts can be marked both sides with dry erase markers. Virtually tear-proof; spring roller; pull-down ring; chains for hanging when using back side. Size 48 X 65 inches. Polar charts have 9 circles from 4.5 to 40.5 inches diameter in 2.25 inch radius increments; main radii at 15o.