If you're looking for the best car diffuser, this is it! This aromatherapy essential oil diffuser by InnoGear is the perfect size to fit in the cup holder of your vehicle, easily charges via USB, and has both a continuous use & an intermittent setting so you only need to run it as much as you see fit. When the water runs out? No worries - it will automatically shut off!\r\n\r\nWhy We Like It - InnoGear Essential Refresher Ultrasonic Aromatherapy\r\nThe InnoGear Essential Refresher Ultrasonic Aromatherapy Diffuser is a great way to take a car that reeks of cigarette smoke and make it into a great smelling vehicle that smells of your favorite essential oil!\r\n\r\nPerformance\r\nThe InnoGear aromatherapy essential oil diffuser & humidifier easily provides a cool mist aroma. Room or vehicle (or anywhere else you place it), this portable cool mist aroma diffuser can add a pleasant smell anywhere you place it, and the scent can quickly be changed just by switching out your choice of essential oil in the water. It is powered by a USB port, so you can power it from your vehicle, a laptop, or a USB wall adapter (if you prefer something that doesn't need a power source, the RoyAroma 30mm Car Diffuser Vent Clip is an electricity-free alternative).\r\nDesign\r\nAt 4.92" in height and weighing in at only 0.28 lbs., this InnoGear oil diffuser ultrasonic portable device is the ideal size to place in your car's cup holder. It uses a USB port as a power source, although it lacks any USB ports on the actual ultrasonic portable cool mist device (if you want an essential oil diffuser that can also charge your devices, check out the Gulaki Diffuser Essential Oils Multifunction!). You operate it with easy-to-use buttons on the top of the device. It even has a waterless auto shut off feature, essentially eliminating any concerns of dry burning.\r\nValue\r\nThe pricing of this diffuser ultrasonic portable cool device is fairly standard, at $19.99 per device (the YJY Car None Sponge Wick Aromatherapy Intermittent is another mist aroma room freshener that costs $19.99). It has free delivery\/returns, and there are a variety of coupons and special promotions that you can use to save a little bit more money. As we expected, there is no warranty offered for this product, but judging by its 4.3\/5-star rating on Amazon, it is unlikely that you would need one anyway.\r\nInnoGear Essential Refresher Ultrasonic Aromatherapy Wrap Up\r\nThe InnoGear Essential Oil Diffuser Ultrasonic Aroma Diffuser is our #1 pick for a reason. This device is the perfect size for portability, can be used with any essential oils, is powered via a USB port, and can even double as a night light! As previously mentioned, there is no warranty offered on this product, but we doubt you'll need one. You can't go wrong with this essential oil car diffuser.