Galvanized Pontoon Boat Trailer Metal Y-Guide Brackets For 1-1/2" Square Posts(2) Pontoon Y Guide Post Brackets 1 5 8" Opening to Fit 1 1 2" Square Posts Secured with Bolts ( Not Included ) Sold In Pairs 7 Gauge Galvanized Metal Brackets Brackets Fits 1 1 2" Square Posts (Not Included) Each Bracket Base Measures Approx. 5" by 5" Secures 1 1 2" Square Tubing Vertically or Horizontally Mounting Base Round Holes Accept 1 2" Diameter Bolts. Distance center to center on holes is 3 1 2".. 2 Hexagon Bolt Holes Are Used For Adjustment