BUCK STOVE Model ZCBBXL VENTLESS GAS FIREPLACE Insert WITH BLOWER. Create the look of a masonry fireplace with theBuck Stove Model ZCBBXL zero clearance fireplace. There are two sizes available; one that has a36″ viewing window and another with a 42″ viewing window — this refers to the total width of the windows on the doors that you can see the fire burning inside of the unit.