http://www.putfile.com/media.php?n=Gravity_Bong Took me about 5 minutes. 1 2-liter soda bottle 1 Sharpie marker, saw off the ends up the black part, then shove a bowlpiece into it and screw it tight. Melt the bottle cap so you can jam the stem through it. le m00. 0_o I used tobacco for legal purpose only. These are the hardest hitting bongs of all, people pass out from just one hit off em. You be the judge.