1/4" / 6.4mm sandwich spade connector. Pure Copper contact is direct Gold plated to protect against tarnish and oxidation. High current spade lug with elastomeric shock absorber for progressive contact pressure eliminating structure born and air born noise as well as magnetostriction. Fully insulated body is safe to use and conforms to international safety standards. Warning against usage of contact cleaners: their contents may cause damage to polycarbonate insulators.