Enviro G Series Glass Burner Traditional Gas or Propane FireplaceOffering realistic flames, large viewing areas and a clean "non louvre" look, the G series is an unbeatable option. The G39 features 40,000 BTUs, a tempered glass window with a large viewing area and multiple ways to customize the look of the fireplace to suit your space and style. Install the Cool Surface system which helps reduce wall temperatures to make installing a TV or decorating your wall above your fireplace safe and easy.