Kauv ntsia hlau pawgnrog txiv ntseej series tuaj yeem muaj 3 txiv ntoo, uas yog qhov ntau tshaj plaws. Kuj tseem muaj 6 txiv ntoo. Peb tuaj yeem txuas cov txiv ntoo raws li qhov sib txawv ntawm cov neeg siv khoom. Nyob rau hauv ib txwm muaj xwm txheej, cov txiv ntoo yog M16 yog cov pawg ntev, yog tias pawg luv luv, M8 txiv ntseej kuj tuaj yeem welded. Lub luag haujlwm ntawm cov txiv ntoo yog kho cov yeeb nkab sab hauv nrog bolts tom qab.
