I have two hawkes 6.5-20x42's but the screw in lens covers are not interchangeable what gives ? One is a (6.5-20x42 half mil dot) the other is a (6.5--20x42 20x1/2 mil. dot.) I would have thought the eye piece & objective lens would be the same but no way .I tried calling the manuf. but must be off for the holiday & haven't seen anything on their site for the right size. I need it for the 6.5-20x42 20x1/2 mil.dot. Maybe I missed it . Thanks in advance