GROCO Backing Block f/2" 2-1/2" Seacocks [BB-3] Cartography | Humminbird The nylon bag features a

The nylon bag features a sewn-in rigid ring that fits neatly into the deck plate to secure and support extra weight in the bag

Filters to 150 microns

Mag Alloys

All 12-gauge 304 stainless steel construction with Electro-Polished Blades

Simrad and Furuno

GROCO Backing Block f/2" 2-1/2" Seacocks [BB-3] Cartography | Humminbird The nylon bag features aBacking Block for 2" & 2 1 2" Seacocks Features: 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 Specifications: