The VBG Jackknife Indicator accessory alerts the driver in the event of jackknifing. If the Jackknife Indicator experiences deformation, the coupling must be demounted to ensure no damage has occurred. For coupling VBG 795V/795V AM/795V PA/795VR and VBG 750V/750V AM/750V PA in combination with drawbeam DB 75V, DB 75V-2 and DB C7.