The Circles/筒.
Instead of 4 suits in a deck of playing cards, you have 3 suits, running from 1 to 9 rather than 1 to 10. The circles are one of these suits, standing for gun barrels.
One Circle. Chinese character: 一筒 /yī tǒng/
Two Circle. Chinese character: 二筒 /èr tǒng/
Three Circle. Chinese character: 三筒 /sān tǒng/
Four Circle. Chinese character: 四筒 /sì tǒng/
Five Circle. Chinese character: 五筒 /wǔ tǒng/
Six Circle. Chinese character: 六筒 /liù tǒng/
Seven Circle. Chinese character: 七筒 /qī tǒng/
Eight Circle. Chinese character: 八筒 /bā tǒng/
Nine Circle. Chinese character: 九筒 /jiǔ tǒng/