Our Zen Petite refillable liquid glass oil warmer and candle (votive size) is an eco-friendly alternative to wax, disposable oil candles and Berger oil lamps. The refillable oil warmer candle's diameter is 2” wide at the top, 1-7/8” wide on the bottom and 2-1/2” tall. The candle holds about 2 ounces of lamp oil. We call the glass shelf that sits 3/4" below the rim, the "Aroma Deck". This is where you can safely drip your essential oils without fear of burning them. The heat from the aluminum wick collar will warm and "blossom" or "throw" the fragrance. Please note, the aroma deck does not get as hot as a tea light burner and, therefore, the scent may not be as heavy. The candle flame is also protected by the integrated windshield. Important: 3 to 4 drops of essential oil is all you need. Add oils when the wick is NOT lit. IF you add too much fragrance, no worries, just continue to use. We recommend using a 32-ounce bottle when filling with the funnel as a gallon container is unwieldy. We recommend wiping out the essential oil after use. We recommend using Firefly Clean-burning fuels.