The Fish-Skull Articulated Fish-Spine is an innovative system of interconnected, articulated shanks that combine to form a multi-jointed "fish spine" upon which incredibly animate and realistic baitfish patterns can be tied. The product includes 4 different lengths of stainless steel shanks ranging from 25mm down to 10mm, making it easy to tie a tapered body for life-like action. 6 sets (24 segments) per all-sizes pack.