The Gray Kangaroo Personal Liquor Filter (currently in it's fourth design) uses the same technology that the liquor companies use to improve the quality of packaged liquor. The Gray Kangaroo works with all pre-packaged hard liquors: vodka, whiskey, rum, gin, tequila. Most people agree that it works best with vodka. What it does is remove particulate matter and harmful toxins while leaving delicious filtered liquor. Filtered liquor (especially vodka) is competitive with brands that cost three times the price. Try it: you will be amazed and never go back to high priced booze. Our customers aren't customers they're fans! Even if you believe in this product, you have no idea how cool it is until you try it!