Today, I had an idea...Madvapes has the best cartos on the planet, but it could be a pain filling at work for me..I wouldn't look to normal with a syringe in my hand when a customer shows up..So what I did when I got home was, I cut a white carto cap and inserted it in a drip tip. I checked to see if the juice ran down the center air hole in the carto...It did not, It was easy and I didn't have to tip the carto about worrying about juice in the center...So maybe you could design a carto fill tip, with three holes on the outside, so the juice runs down the sides of the carto, have plenty of air to vape, and won't have to remove tip to fill...
Yeah Baby!!!
Yeah Baby!!!
