Fremco chain set 103-211025001 covers fiber optic cable from 4 mm to 12 mm on MiniFlow blowing machines and is priced per each. The chain grips the cable jacket and pushes it into the duct in coordination with the air stream, so the pad profile has to hold firmly without crushing tight-buffered or micro cable. The 4-12 mm range spans most drop and small-count distribution cable used in FTTH. Chain sets are wear items and are replaced when grip degrades. Available from Millennium as part #527118.