Backing Block for 2″ & 2-1/2″ SeacocksFeatures: Each size fits multiple seacock sizesPress threaded brass inserts into the hull side of the backing block into the holes that match the seacock flangeRigid 1/2″ thickness provides secure installation but is flexible enough to conform to minor hull curvatureWill not swell or absorb moistureMade from an environmentally friendly PVC foam specially formulated for marine applications Specifications:Construction: BronzeBox Dimensions: 1″H x 7″W x 7″L WT: 0.45 lbsUPC: 742985170155