English to Spanish Tech/Engineering Ships, Sailing, Maritime Osmosis treatments

Dos párrafos del mismo texto en los que aparece la expresión:

"The removal of a glassfibre core – such as the ‘plug’ that is removed when a skin fitting is installed – can give a great deal of information."

"It will also protect metal fittings from corrosion, and so a single product can be applied to hull, sterngear and skin fittings to provide maximum protection to all underwater parts of the vessel."

He encontrado fotos de "skin fittings" en Internet, son algún tipo de pieza o anclaje. ¿Alguien sabe el nombre en español?
¡Muchas gracias!
AA