ZDM / Galvion zinc anode elements are stacked to provide greater surface area and longer lasting performance than conventional pencil zincs.
Each zinc element has a threaded steel core that's cast in to enable the elements to interlock with each other, and reinforces the zinc until completely consumed.
ZDM-500 Engine Zinc Anode Element
3/8" NPT Brass Plug for ZDM-500 Zinc Anode Elements