Davis J-Base f/Windex 15 Drill A Pilot Hole In Mast, Apply Silicone Sealant Or Locktite And Screw Into Mast. Installation Of J-Base Can Also Be Accomplished By Tapping The M This Optional Mount For Windex 15 Provides More Versatility And Reduces Overall Weight Aloft By 15 Grams When Substituted For Standard Windex 15 Mounting Base. Box Dimensions: 1"Lx1"Wx1"H. Weight: 0.2 lbs.