When your BARR-CO diffuser runs out of oil, it is nice to just be able to refill the oil and not have to purchase a whole new diffuser set. This oil refill comes in an amber glass bottle, which is shatterproof for safe delivery, and the amber glass keeps the oil protected from light until use, maintaining the integrity of the scent, as it was imagined by the designers at BARR-CO Fir and Grapefruit Scent is a juicy grapefruit zest and the clean fresh woodsy notes of fir oils create an intense rush of invigorating, yet comforting notes. Made with plant extracts and soothing botanicals.