Poisson Du Jour
Member
Replacement foam around the lower perimeter of the TTL prism is a compress-fit once new. It has to be like that. I replaced the foam of my prism 3 years ago, and once in a life time is quite enough! Over time, the compression will wear down (removing and reattaching the prism very often will decrease the compression). A very firm push down until the tell-tale clicks are heard should be sufficient. But replacing the foam is a ghastly sticky chore involving fingers, blades, Q-tips, alcohol, tissues, tears and some novel swear words... a whole range of ever-increasing implements and requiring a lot of time.