Well it arrived this morning and as the ad had stated it was absolutely mint and according to the seller, had only been used once. I hadn't picked up on this issue when reading reviews but it needs a fair bit of strength to fit it onto the Olly 5 mkll. I've googled it and am now aware of the issue and the fact that some have returned the lens fearing damage to the Olly mount or debris getting inside. It's mounted now so I have decided not to worry about it as I won't be taking the lens off and on the body. The going price in Oz is between $1700 and 2000 and as I got this for $1300 I've decided to grin and bear it Managed to get 2 shots off in the garden to test but then it started to storm but those two shots tell me that the lens is promising.