Twebwe (CNG) dutanga umusaraba ugabanya umusaraba. Bakoreshwa muguhuza Standpipe kugenzura, gukwirakwiza, cyangwa gushyigikira umuyoboro mubunini cyangwa icyerekezo. Kwihuza na groove, umushinga wigihe wabitswe cyane hamwe nogushiraho byihuse no kubungabunga byoroshye. Dutanga ibyuma bifata imiyoboro ya sisitemu yo kurwanya umuriro.