The 'Candela' jar is modelled after the old fashioned milk and cream bottles. Most importantly, the 'Candela' jars have been specifically designed by engineers for candle use. The slope of the jar walls effectively keep the heat inside the jar making it a perfect to create a heated wax pool, all the while giving a maximum fragrance and even burn characteristics. They use essential oils and the wicks are 100% cotton, to ensure a clean burn. Made in Canada