... 1)Efficiency:82%; 2) SIT valve, firebox, burner, gas logs, black louver, blower G33 features: 1) 33 ... : 82%4) Fuel: Natural gas/LPG5) High-temperature glass6) SIT valve, firebox, burner, gas logs, black louver, blower7) D ... Efficiency 82%4) Fuel: Natural gas/LPG5) High-temperature glass6) SIT valve, firebox, burner, gas logs, black louver, blower7) ... 20' FCL: 68pcsQty/40' FCL: 148pcs G33/G36 Gas Fireplace