Built with two opposing magnets to hold the pliers open, the Mag Spring mechanism cannot fail, unlike conventional plier springs. The split ring nose on the 4” model opens rings from size 0 up, while the 18 cm pliers are ideally suited for size 3–5 rings. The cutter on both sizes cuts all line sizes. The pliers feature stainless steel jaws and co-molded grips. Only 18 cm pliers come with a molded plastic sheath. 15 cm model doesn't include a sheath.