Most spills occur tipping a normal can to get the spout into the tank opening before the liquid comes out, or removing the spout from the target vessel before overflowing. The No-Spill spout is fully user controlled so you tip the can vertical, insert the spout into the vessel opening, then press the button to begin and control pouring. To stop pouring simply release the button. Practically eliminates spills and overflows. The only Spill-Proof spout with thumb button control that does not push down on your tank s filler neck to pour. More control, fewer tip-overs of your small equipment. The fastest pouring Spill-Proof nozzle availble.