Keep moisture, dirt, and debris from entering your oil reservoirs. The silica gel inside these breather vents absorbs moisture from the air, preventing rust from forming inside your tanks. The gel changes from blue to pink as it becomes saturated, letting you know it needs to be replaced. A second filter blocks dust and other particles from getting inside. These breather vents allow air to flow in and out of your lubrication system, keeping excess vacuum or pressure from building up in cylinders, gear boxes, and tanks.

For an extended service life, use breather vents with a steel body. They are stronger than breather vents with plastic bodies and hold up better when exposed to chemicals. A window lets you check the color of the gel. No need to replace the entire unit when the gel is saturated—use rebuild kits to add fresh gel and to replace the window, filters, and gaskets.