Cuff for air delivery tube

FIG. 1 is a perspective view of a cuff for air delivery tube according to our new ornamental design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a reverse perspective view thereof.

The broken lines represent environmental structure and do not form a part of the claimed design.