All the reed diffusers at WattieWicks Candles are made with a vegetable glycerin base, and 25% of fragrance. Each diffuser is 100ml, and comes with 7 x 5mm fibre natural coloured reeds, which are perfect for scent great diffusion, and they need turning far less than traditional reeds. For maximum fragrance, don't put your diffuser near a heat source, or on a windowsill. Each diffuser comes in a 150ml bottle, allowing a gap at the top to reduce unwanted evaporation, and minimises the risk of spillage when inserting the reeds.