Our Aluminum Oval Sleeves are made from high quality aluminum, providing for secure connections for all of your monofilament and fluorocarbon leaders. With six models available, from 1.5mm (G), 1.7mm (F), 2.0mm (E), 2.3mm (D), 2.8mm (C) and 3.3mm (B). ensure you have plenty of crimps on hand when the bite gets hot, and leaders need to get swapped out.