From the manufacturer:
Our 16″ (40 cm) Knit RED™ line of surgical stainless steel circulars have a smooth, satin-sheen finish and memory-free, multi-strand, steel cable coated with red nylon allowing yarn to slide right over. The precisely machined tips are ergonomically designed with a bend to ease hand fatigue. Needle size is permanently laser imprinted on each circular. The joins are just spectacular!