Description
- Exhaust Seal Ring For Trophy Plus Propellers (Blow Out Ring)
- Also Fits PowerTech TRO4 Propellers
- Genuine Mercury Part# 878421 – Dimensions: Inside 3.7/8″, Outside 4.13/16″
- Prevents “Blowout” by filling in the gap between the prop and the gearcase
- Converts 4-1/4″ Trophy Style Propellers to fit 4-3/4″ gearcase
- Reduces ventilation
