Raypak Left & Right Refractory Common For 207A-407A | 010079FRaypaks 010079F Left & Right Refractory Common Kit supplies the two refractory blocks required for proper firebox protection in 207A, 267A, 337A, and 407A Low NOx digital heaters. These OEM blocks act as flame shields, protecting the firebox walls from direct heat exposure while ensuring efficient combustion. When refractory material becomes worn or cracked, this kit restores the heaters flame pathway, prevents energy loss, and reduces the risk of