Frame for respiratory mask

FIG. 1 is a front perspective view of a frame for a respiratory mask 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 rear perspective view thereof; and,

FIG. 6 is a side view thereof.

The broken (dash-dash) lines showing environment or structure are for illustrative purposes only and form no part of the claimed design.

The dash-dot-dash lines indicate the boundary between claimed and unclaimed subject matter and form no part of the claimed design.