A molded cup-shaped item having a small aperture in its apex. The aperture is designed for releasing the excess sealing cement applied in the cap prior to use. The item is designed to create a tight seal around bolt heads, nuts and rivets where a tight and effective seal is required, such as airplane integral fuel tanks. Also used for antichafing protection. Excludes boot, dust and moisture seal and cap, pprotective, dust and moisture seal.