Protective rubber insert for couplings types VBG 750V, 750V AM, 750V PA, 795V, 795V AM, 795V PA, 795V-2, 795V-2 AM, 795V-2 PA, 795 VR, 795VR-2, 7310D and 7310D-2.The insert protects the coupling bolt from dirt and prolongs the service life of the mechanism. Resistant to oils and grease.