Osburn Matrix 1900 Wood Insert (OB01900), EPA 2020 certified wood-burning appliance from the Osburn 2026 Tri-State Distributors price list (effective March 1, 2026). Compact insert for smaller masonry fireplace openings (min. 19" H x 25" W x 15 1/2" D), rated up to 45,000 BTU/h at roughly 80-82% efficiency. 1.1 ft³ firebox accepts logs up to 17 in; tapered top and sides ease installation, with a flush-mount 90 CFM blower and ceramic glass door. Recommended heating area: 250 - 1,200 ft². Maximum burn time: 7 h. Required: select your Door Overlay below — these are separate, required components priced individually and must be chosen to complete checkout; they are not included in the base price shown here.