This is a 120mm diffused downstem from Gear Premium, the part that carries smoke from the bowl down into the water. The diffuser slits at the base break the smoke into smaller bubbles to filter out debris and spread it evenly through the water, which cools and smooths the draw compared with a plain open stem. The ground joint is designed to come out easily for cleaning, and it carries a gold Gear Premium decal. Check your bong's joint size and the length you need before buying, since a downstem has to match the piece. A reliable replacement or upgrade in borosilicate glass.