I put it in a V4 case and I was surprised how easy the original crystal came out. The gasket stayed in the case and I just popped the Sunnydale crystal in. It went in pretty easy but I'm not sure it was any different than the one that came out. It seemed to be identical in both size and thickness to the V4 crystal when side by side.
As it is currently, I wouldn't want to take it swimming without re-setting it with watchmaker's crystal glue.
As it is currently, I wouldn't want to take it swimming without re-setting it with watchmaker's crystal glue.