Check the listing for details. E-2 Engine Zinc Anode 1/2" NPT x 2". Condition: New. Listed at 14.00 USD. E-2 Engine Zinc Anode 1/2" NPT x 2" length. Plug NPT= 1/2". Engine pencil zincs complete with end plug. Wrench size: 7/8. Picture is of a larger size for reference. Cu % 0.001. Fe % 0.001. Zn % Balance.