Sais
A Sai is a short unsharpened metal dagger, often used in pairs. It is hypothesized that sais are descended from a planting and digging implement, or a cartwheel pin. They are used throughout Asia, but are most often associated with the Okinawan weapons. The central spike on a sai is the baton, the two side pieces are yoku, and the heavy mass on the base of the handle is called the knuckle, and is often used for striking. Traditionally, sais are primarily defensive weapons and are designed and taught primarily for use against swords.