It's called a boondocker kit. It pressurized the fuel bowl according to nitrous pressure. So it's only when you push the button it will add more fuel. It works great. I used one on a twin cylinder snowmobile back in 06. 50hp shots. I probly put 2000 miles on that setup and went through at least 20 4lb bottles. No issues. But the initial tuning took a couple days to get it dialed. I run a dry system on my fuel injected twin with a control box. It dumps Extra fuel whenever the nitrous solenoid opens. I have 3000 miles on it with that setup with 50 HP shots on pump gas. No issues. I have installed the boondocker kit on a polaris predator 450 for a customer. Got it close on tuning and he loved it never had an issue. 25hp shot on pump gas.