This optional wall sleeve for the large wall mounted fire-rated pet door will be necessary if your stud walls are deeper than 2 x 4 walls (4 5/8″ thick).
We are a family-owned company based in Petaluma, CA. We are the original inventors and designer of the only UL tested and certified – National Fire Protection Agency Approved fire rated pet doors.
FireSafe Pet Doors LLC
89 Center Rd, Petaluma CA 94952-1028 USA