Standoff Extension BarRigid extension of 1/-4-inch thick (6.4 mm) aluminum. 16 inches long (406.4 mm), 1 inch wide (25.4 mm). If your masthead is crowded, or you want cleaner air for the Wind Instrument, extend this in front of the mast and mainsail. The hole pattern is the same as the foot of the Wind Instrument. Includes 4 pairs of stainless steel #8 machine screws (5/8-inch) and lock nuts.