Here is what is known as an explosion whistle that will screw into the primer hole of a gas engine. When activated it will make a whistle sound when the engine fires. There might be a very slight crack in the threaded mounting area. Check out the pictures and see if you need it. The bell is about 2 in diameter. 1/8 pipe mounting, those threads might have a slight crack. The valve seems to work fine but I haven’t tried it under any pressure. “AS IS” what you see is what you get. For questions 419 789 1159. Thanks for looking at this listing! If you want to check out my reputation and such please feel free to google search my name. My name and address is. 14316 State Route 281. If you can find a way to talk to me with your voice you will almost always get a quick response. If you message me please try not to sound like a caveman. I have terrible grammar myself so I understand but sometimes it is very difficult to comprehend what some people write. If I make a mistake on my measurements or you feel something is not as described please let me know and I will try to make it right. I think most all of my customers with a normal level of sanity are happy. I think most people would agree that I do an extremely good job of packing items so I guess it’s worth the wait. Check out my other items. Be sure to add me to your favorites list.