This hardware set is designed for 1/4" RMGI, ATR, 3M, or AMPEX metal NAB three screw take-up reels.. It contains 24 tested and matched screw fasteners (barrel bolts) with 24 high quality stainless steel screws for physical strength and to avoid the screw seizing. These hardware sets are a must if you're working with pancakes or if you often swap out flanges. Each pack will fasten Eight 3 hole NAB flanges together.”