A zinc water filter anode for the Frigoboat Keel Cooler marine refrigeration system. Two anodes required per unit on the exchanger plate - small recessed areas for anodes to be positioned. Original part number E51525 like Martyr version CM51525Z. 

The zinc anode is made in Italy to an extremely high specification (US MIL Spec), with the entire melting and casting process performed to ISO 9001 standards.

Every heating and cooling anode sold by Anode Outlet is genuine and manufactured to the highest quality anode specification. Item(s) shown in image may not come in manufacturers' branded packaging due to production processes.

Excerpt from Frigoboat manual:

If the Keel Cooler being installed is the type without zincs, it must be connected to the vessel€™s bonding system and also to a sacrificial zinc anode. This is an important safety precaution and does not alter the fact that a connection must be made between the Keel Cooler and a point that is at the same potential as the boat€™s battery negative, whether the Keel Cooler has zincs or not. Bonding wire should be green in colour and of 8 AWG or higher.

Specifications:

Please refer to the diagram in the product images.
h: 26mm.
Ø: 35mm.
Ø1: 5mm.
Weight: 0.04kg.

Useful Links:

Blog: How often should a sacrificial anode be replaced on a boat?
Blog: Cathodic protection for boats.
Blog: Aluminium versus zinc anodes.