This weekend I'm going on a mission to Home Depot to find replacement tubing and o rings for Ce2 clearomizers. I plan on bringing a few clearos with me for sizing and so on but was wondering if anyone knew what internal diameter of the tube is? I currently use 510 XL clearos. I should probably invest in calipers for future ventures and I'm sure won of the workers there will have some but I'd kinda like to know a little more going in then i already do. I also have decided on two materials to try as well polycarbonate like the map tanks, and low density polyethylene like the juice bottles. If anyone knows of something else i should be looking for please let me know I'm no chemistry major but i figure those materials are safe since they are in common use now.