Wikipedia
Hanbō
The hanbō (半棒, lit. "half-staff") is a staff used in martial arts. Traditionally, the hanbō was approximately three shaku or about long, half the length of the usual staff, the rokushakubō ("six shaku staff"). Diameter was . However, depending on the school the length and diameter varied.
As with any weapon, bearers would often find one best suited to their build, opting often for one that comes up to about waist/hip height.