Lesi sakhiwo somshini iphethini yohlobo lwamarola amathathu alinganayo, irola ngama-symmetrical amabili amaphakathiIsikhundla ngaphansi kwerola sihamba siqonde ku-screw worm kanye nomama kasilika, Amabili aphansiAmarola azungezisa okukhiphayo kwesinciphisi segiya kanye namarola aphansi I-Gear mesh, ukuze inikeze itorqueI-roll sheet. Ububi bomshini ukuthi ukugoba kwepuleti lokugcina kudinga ukusetshenziswa kwamanye amadivaysi.