ChiaoGoo SPIN interchangeable tips are crafted from Premium Moso bamboo and feature a smooth, free-swiveling nylon joint.  They come in 4″ (10cm) or 5″ (13cm) lengths and are fully compatible with all other ChiaoGoo [S] or [L] cables and accessories.   The 4" tips with an 8" cable makes a 16" circular needle.  The size is imprinted on each tip.  Spin Tips can be used with TWIST red cables.