The aluminum pencil anodes are more suited to the heat exchanger and engine environments than zinc. Aluminum can be used in any water from fresh to salt (as recommended by ABYC). They provide better protection and are environmentally more friendly than zinc. They last up to 30-50% longer than zinc. They are made to MIL-DTL-24779B(SH) specification.
The “Securecore” central wire helps prevent the wasted end from falling off and blocking the waterways of heat exchangers and engines.