Mailing Tube with Rectangular Exterior

FIG. 1 is a front perspective view of a mailing tube with rectangular exterior showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a top plan view thereof, the left side elevation view, the right side elevation view, and the bottom plan view being identical images thereof; and,

FIG. 4 is a cross-sectional view thereof, taken along line 4 - 4 of FIG. 2 .

The broken lines shown in FIG. 4 depict portions of the mailing tube with rectangular exterior that form no part of the claimed design.