Attwood Thru-Hull Connector #23-665473 Hose: 3/4". Flange OD: 1-7/8". Barb Length: 1-1/4" Max hull thickness: 1-9/16". Stem: 3-23/32". Cast 316 Stainless Steel. A channel under the flange holds a bead of sealant. All models have wrench flats or an end notch. Designed for installation above the water line only.