The big size wicks burn for approximately 20 to 25 mins. They are perfect for daily puja, where you can do the puja and by the time you leave home you're sure the wick has finished burning. These wicks are a replacement for your handmade ghee diyas, so there won't be any strong smells when you burn it. After it's fully burnt, there will be a small black dot left in the lamp. Throw it away and your lamp is ready for your next meditation. Each box has 30wicks.