PayandPack Myard DELUXE 18" inches SIERRA BIRCH Fire Gas Logs (LOGS ONLY) for Natural Gas/Liquid Propane Vented Fireplace HEAVY DUTY, not foamed alumina ceramic or glass (light & fragile). The logs are steel reinforced, plus produced with lave granules plus significant heat ceramic refractory which is employed to check rocket machines. Designed to be Used With Vented Gas Log Systems. Highly detailed, hand painted refractory firelogs. By 3 generations of designers, logs are designed, handwork manufactured in CA USA. Type: 18" 5-LOG set SIERRA BIRCH style Vented Gas Logs. Approved Certification is through OMNI TESTING LABORATORIES. Indoor gas logs sets have limited LIFETIME WARRANTY by manufacturer.