For Two-piece, pancake-style zinc anode for rudders and trim tabs.
Diameter: 5″
Thickness of One Half: 5/8″
Screw: Stainless Steel Socket Cap, 5/16″-18 Threads, 1-3/4″ Length
EMP Zinc anodes conform to Mil-Spec: MIL-A-18001K

also crosses with:
Canada Metals CMR04
Performance Metals R5000Z
GLM 26654
Technoseal Technoseal R4
Camp R-04
Reliance MDR-4