A "bō" is sometimes called a "rokushakubō" (六尺棒: ろくしゃくぼう). This name derives from the Japanese words "roku" (六: ろく), meaning "six"; "shaku" (尺: しゃく); and "bō". The "shaku" is a Japanese measurement equivalent to 30.3 centimeters (0.994 ft). Thus, "rokushakubō" refers to a staff about 6-"shaku" (1.82 m; 5.96 feet) long. The "bō" is typically 3 cm (1.25 inch) thick, sometimes gradually tapering from the middle ("chukon-bu") to 2 cm (0.75 inch)at the end ("kontei"). This thickness allows the user to make a tight fist around it in order to block and counter an attack.