Pleasant Hearth Glowing Ember Fiber, 4 oz. Pleasant Hearth's Glowing Ember Fibers (Rock Wool) provide the same effect of a glowing bed of ashes in a wood-burning fire. For best results use as directed in your owner's manual. Pair with Lava Rock (LVR100) for enhanced look - sold separately. Made in the USA. 1 Year Warranty. Features Vented or VF Ember Burner Log Sets Only Add realism to gas logs creates the illusion of a realistic burning ash bed Longer Life Expectancy Pair with Lava Rock (LVR100) for enhanced look - sold separately Made in the USA; 1 Year Warranty USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.