I have a pair of Conquest HD 8x42 binoculars. I tried to put the replacement longer eye-cups that Zeiss sent to me on my binoculars, but I cannot completely retract those eye-cups to my binoculars. There are gaps in between. Are they supposed to be like that? I tried to contact their customer service, but I did not receive a reply. I have attached photos in here. Many thanks.