It?s easier to direct where the oil goes without messy drips or spills. b-Roller ball more smoothly, give better control of the amount of top oil, mo leakage absolutely! c-No need to measure drops in your palm, release your hands from slimy liquid. d-Easy to use, just roll on, then use fingertip to massage and you are done. 2)Premium Features of Roll on Bottle: a-Made of corrosion-resistant Plastic, safe and reusable, simple to clean. b-Roll on plastic bottle protects against sunlight and UV rays, great for light-sensitive liquids. c-Good storage choice for essential oils, perfume, or other liquids. d-Easily fits in your purse, perfect size for travelling, carrying outside, home & office using."