Martyr Zinc Rudder Anode Set 5 Inch CMR04S
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The Martyr CMR04S is a zinc rudder anode set designed to help protect rudders and trim tabs from galvanic corrosion in saltwater use. Current product references describe it as a streamlined rudder anode set with hardware included, built for marine corrosion protection on exposed underwater metal surfaces.
Key Features
- Zinc sacrificial rudder / trim tab anode set
- Martyr part number: CMR04S
- Designed for saltwater use
- Approx. size: 5 in. diameter x 5/8 in. thickness
- Streamlined split-anode design
- Commonly supplied with slotted combination fasteners / hardware
Application / Compatibility
Designed for rudder and trim tab applications where a 5-inch split zinc anode is required. This is a general marine hardware fitment item rather than an engine-serial-number-specific anode, so matching by diameter, thickness, mounting style, and current installed shape is the safest way to confirm fitment.
Serial Number Fitment Notice
Please confirm fitment by comparing your existing anode’s outside diameter, thickness, and attachment style before ordering. For rudder and trim tab anodes, physical match is more important than engine model fitment since these are used across a variety of boat setups.
When This Part Needs Replacement
Replace this anode when it becomes heavily wasted, pitted, cracked, loose, or significantly reduced in size. Rudder and trim tab anodes should be checked regularly because they are designed to corrode first in order to protect more expensive underwater metal components.
Installation Notes
Install on a clean bare-metal contact surface and do not paint the anode. Current references indicate this set uses slotted screw fasteners / combination fasteners, so verify the included hardware matches your current installation before service.
Alternate / Superseded Part Numbers when applicable
- CMR04S
- CMR04
- 22-3122
Parts Desk Insight
Rudder anodes are easy to overlook because they are simple bolt-on parts, but they protect large underwater metal surfaces that stay exposed full-time. A 5-inch split anode like this is a common service item on boats that spend long periods in saltwater, and replacing it on time is much cheaper than dealing with corrosion on the rudder or trim tab itself.
Shipping
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.