Refill oil for our concrete diffusers. Diffuser refill in glass test tube. 60ml, 40% fragrance. Lasts 3 months. Made by NicolaEach product Nicola makes effuses a deep sense of place, nature and connection. She fashions concrete into vessels that feel rustic and familiar. Her scents evoke an earthiness that are grounding and signify a sense of home. Each gift she makes is a little bit of domestic glory.