Product Description
The Friedrich Wallmaster baffle adapter kit is necessary when installing a Wallmaster thru-the-wall air conditioner in a sleeve deeper that 16 3/4" deep, such as a Fedders B sleeve. The kit comes complete with baffle and mounting hardware and extends the Wallmaster unit to 19 3/4" deep
From the Manufacturer
Disclosures

Cancer and Reproductive Harm - P65Warnings.ca.gov
The Friedrich Wallmaster baffle adapter kit is necessary when installing a Wallmaster thru-the-wall air conditioner in a sleeve deeper that 16 3/4" deep, such as a Fedders B sleeve. The kit comes complete with baffle and mounting hardware and extends the Wallmaster unit to 19 3/4" deep