You can choose from four models: the Mini, Version Four, the Plus, and the Car Pro. The Pura Version Four is the standard and commonly sold in starter kits that provide the diffuser and two scents.

I’m something of a home scent obsessive. I’ve tried most scented candles on the market, used everything from laundry sprays to plug-in air fresheners, and always have a diffuser on the go. The best ...