Martyr Anodes CMEZ5 3/4" x 3-5/8" Pencil Zinc Engine Anode - Zinc Only

The Martyr Anodes CMEZ5 is a replacement zinc-only pencil anode designed to protect marine engine cooling systems from galvanic corrosion. Measuring 3/4" in diameter and 3-5/8" in length, this anode threads directly into your existing brass plug — no plug replacement required.

Zinc is the recommended material for pencil anodes used in engine cooling systems. Unlike aluminum anodes, zinc pencil anodes will not break at the neck and block critical coolant passages — a key reason why major engine manufacturers continue to specify zinc for this application. This anode is formulated for use in saltwater environments.

Key Features:

• Zinc-only replacement — threads into existing brass plug
• Dimensions: 3/4" diameter x 3-5/8" length
• 3/4" NPT threaded head for secure installation
• Zinc alloy manufactured to meet or exceed U.S. Military Specification (MIL-A-18001K)
• Chemically tested for alloy consistency and performance
• Recommended for saltwater use
• Protects engine heat exchangers and cooling system components from galvanic corrosion

Regular replacement of pencil anodes is essential for maintaining engine cooling system integrity. Cross-reference part numbers: MTR CMEZ5, E-5Z, TEC-E5-Z, CME5Z.