Ciener Ultimate over/under is a type of shotgun that you can use for hunting or shooting targets. The gun is called an "over/under" because it has two barrels stacked on top of each other, with one barrel on the top and the other on the bottom.
When you want to shoot with this gun, you load it by putting shells into the bottom barrel first, then closing the gun, and loading the second shell into the top barrel. This way, you're ready to shoot either barrel, depending on which one you want to use first.
The gun is called the Ciener Ultimate over/under because it was designed and made by a company called Ciener, and it's considered to be a very good and high-quality shotgun. It's called "ultimate" because it's supposed to be one of the best shotguns around.
So, if you want to go hunting or shooting, you might use a Ciener Ultimate over/under shotgun because it's very reliable and a great choice for both beginners and experienced shooters.