Answer: Semi-recessed fire extinguisher cabinets are mounted metal housings usually found in commercial or industrial hallways. They are mounted partially-recessed into a four-inch (4″) metal or wood studded standard wall. Depending on the size of the extinguisher, the extinguisher cabinet protrudes two to four inches (2-4″) from the wall surface.
More information about semi-recessed fire extinguishers:
When reading a datasheet or product description page, the rough opening refers to the opening cut into the wall to accommodate the tub and is slightly larger than the physical outside dimension of the tub. The overall outside trim measurement is the physical size of the entire assembled cabinet, including the front and trim.
The addition of the 1-hour fire-rated double-wall offers increased protection for the cabinet and extinguisher from fire damage, allowing it to remain usable for a longer period during a fire event. Note that the addition of the 1-hour fire-rated double-wall increases the size of the rough opening. When mounted according to the included instructions, Elite fire extinguisher cabinets meet the required ASTM-E119-98 with test report WHI-495-1534.