Earth, Wick & Fire has created a beautiful natural slate, maintenance-free, low-profile candle that you will enjoy for years, just add oil. Our fiberglass wicks do not burn away and each copper wick holder is handcrafted. The reservoir holds 1 oz. of lamp oil and will burn for 5 hours before putting itself out. The addition of essential oils to the reservoir will add a wonderful aroma to your space. Citronella oil may be used outdoors.