Acupuncture Needles are Tools used for healing. They greatly improve the Properties Healing Success Rate, Quality, Min Healing, and Max Healing. Like many Tools that are crafted, they can be made from a variety of Materials. Their effectiveness depends on the Material's Work Speed Coefficient. Higher Tier Materials such as Spiritwood (Timber), Darksteel Bar, and Lumina Core Bar greatly improve their effectiveness.
Their effectiveness is not affected by the final item's Tier or Quality, and as a result do not benefit from Specter Refinement.