Polyamide 6. resistant to UV-rays and marine environment. Elbow thru-hulls are the answer to the most common plumbing issues :

• allow major room saving. as they can be used with a hose running along the hull.
• avoid making a bend in the hose. which can sometimes be a source of leak or breakage.
• require a simplified installation process inside the hull. carried out by one person only. You can hold it firmly with one hand. while screwing with the other hand.