More comfortable to hold than a round needle due to the flat sides and rounded corners. Purposefully calibrated to obtain the same gauge as round needles. There’s no need to “size up” as with other brands. Compatible with all ChiaoGoo cables. Available in 4" and 5" Tips: Sizes US 2 (2.75mm) – US 8 (5mm) have a SMALL [S] size join and work with any SMALL [S] diameter cables. Sizes US 9 (5.5mm) – US 15 (10mm) have a LARGE [L] size join and work with any LARGE [L] diameter cables. Made in China