There is significant variability between orders of these "15-hr" candles. When I ordered them last year, the product lasted 15+ hours and burned completely. This year's product is a different color (pure white vs last year's slightly yellow wax) and rarely lasts 15 hours. I've burned the candles from both years in the same receptacles; so, I know that is nit a factor. This year's candles appear to have a smaller diameter wick, making them frequently self-extinguish when first lighted. When the do burn, they do not generate enough I heat to consume all of the wax. The glass votives always have a ~1/16 in. rim of unburied wax on the sides of the votives, meaning I'm paying for candle wax that is not used. Last year's candles are superior to those available now. Stereo changed the formula of the wax and made the wicks narrower. Not a good decision.