Hollow Metal Frame Latch Mounting Bracket | Mortise Lock Latch 1986-Oldsmobile-Bravada The manual explains this concept

The manual explains this concept in detail with professional insights

With access to 500 code searches

The "B" side is used to depress the cylinder cap pin and turn the tailpiece on Schlage "A" series locks so the knob retainer can be depressed

and keypad door locks

Door Fitting: 1-3/8" ~ 2" door standard

Hollow Metal Frame Latch Mounting Bracket | Mortise Lock Latch 1986-Oldsmobile-Bravada The manual explains this conceptThe LMB 02 mortise lock bracket is designed to be used on metal doors with or without a center seam. Stamped from 11 gage cold rolled steel as the LMB 01 and also mounted with pop rivets (supplied) for ease of installation. The mounting holes are tapped for 12 24 to accommodate existing mortise lock screws supplied by the manufacturer. LMB 02 can be used with Schlage, Corbin Russwin, Yale, Adams Rite and similar mortise locks.