U-Cup seals are vital components in the prevention of oil and lubricant leakage, as their combination of a static outside sealing lip and inside dynamic lip allow them to create the proper pressure for pneumatic or hydraulic systems to operate.

Used for all projects that include hydraulic pressure including lifts, presses and pistons, U-Cup seals help to maintain mechanisms that are free from lubrication leakage, which can damage other components within the project. They can also be known as packing cups, or lip seals.