*** use Option (1) to select Seacock Size ***
Groco Backing Blocks for Flanged Seacocks
- Each size fits multiple seacock sizes
- Press threaded brass inserts into the hull side of the backing block into the holes that match the seacock flange
- Rigid 1/2" thickness provides secure installation but is flexible enough to conform to minor hull curvature
- Will not swell or absorb moisture
- Made from an environmentally friendly PVC foam specially formulated for marine applications