If you're using a basic downstem with your bong that's nothing special, you should upgrade to a tree perc downstem. Your bong hits will be much cleaner, tastier, and far smoother.This 18mm to 14mm Tree Perc Downstem has 6 separate arms that very effectively diffuse the smoke before it reaches your lips. When you add this diffused downstem to your bong, it will be a real game-changer. Your rips will be more powerful, flavorful, and satisfying.Once you try your new tree perc downstem, you'll never go back to using a regular downstem again. Available in several colors, there's sure to be one of these tree perc downstems that fits your bong perfectly.                                                                                                                Inches: 4" | Colors: Blue, White, Black , Green and Dark Blue