Use these fittings to build frames for shade cloth, bird netting, tarps, batting cages, etc. These 16 gauge fittings are gray painted and have 1/4 in. nuts welded in place to accept Allen set screws for attaching fittings to 1-3/8 in. O.D. pipe. This pipe is available from fence companies and building supply outlets in 16, 15, 14 and 12 gauge sizes, usually in lengths of 10 and 21 feet.