I can only speak of my Bosch plug leads , or spark leads .And the trouble i had with BOSCH .The quality looked good. That was untill i was going to to fit them on to the distributor , and the plugs .You know that our leads need a plug conector puller to remove them, and you hear that snap as they are removed . And on fitting them back on .I did not get this . Looking inside the rubber boot it was just a copper crimp on rubbish inside .That was the reason it never made tha noise to say , yes i am in place; So just take a good look at the new leads before you purchase them .I wont be buying Bosch any more .And they are made in China now. After this i am thinking they cpould have been fake .