Circulating/Radiant Firebox, 42" opening, with Refractory Brick standard BUF400 and BUF500 Vent Free Fireboxes Our BUF line of vent free fireboxes from Monessen offer a zero clearance design, allowing you to install next to wood, sheetrock or other construction materials. With a true 36 or 42 inch brick to brick opening, the BUF400 and BUF500 offer a truly expansive view of the flames. Shipped with standard refractory firebox liner and black facing, the BUF series is a versatile vent free option for any design application.

• CSA design certified to fit most 18," 24," and 30" vent free log sets
• Zero clearance design for ease of installation
• Gas knock out available on left and right side
• No expensive flue, or hearth required
• Outside air kit option
• Standard curtain mesh screens for true fireplace appeal
• Standard junction box included for electrical hook up blower kit
• Available with true 36" and 42" fireplace opening
• Shipped standard with refractory firebrick
• Radiant face design with heat circulating air ducts for optional blower
• Can be installed with non-combustible material up to the opening of fireplace for true masonry look