In GLM's Mercruiser replacement 4 inch riser, there are two
additional water jackets. This allows a higher volume of water
to flow through the riser, keeping the engine cooler.
All risers are powdercoated black for maximum corrosion protection
Cast Iron risers come with a 3 year warranty
Manufacturer: GLM Products, Inc.
Mercury Part Number: 807988A2
OSCO Part Number: 4354