75WR-4 Transducer Housing WrenchA single-handed wrench that holds the main thru-hull housing via the 'wrench flats' on the side of the housing to facilitate tightening of the hull nut. Use wrench 75WR-2 or 75WR-3 for the hull nut.For use with: B75 SS75; - cis2:mm5mnJlm -Specifications: Type: Tools; Box Dimensions: 1"H x 5"W x 10"L WT: 0.6 lbs;