Aircraft Aluminum 3/8″ Female Connector, Heavy Duty Carbon Spring Steel Prongs Give Extra Holding Power. Prong Tips are Angled to Open During Penetration. Available with red or purple fittings. *Note – Carbon Steel tips will intentionally rust in order to provide texture for gripping. Even new Carbon Steel 3 Prong Tips may start to show signs of rust, which is normal and not a defect.