You can also use the custom fit leak sentinel from Vividhousing:
I got good email exchanges with the maker, and it's a tiny smart system that provides LED feedback.
Also, he gave me shots of it attached to the Nauticam OM-D housing. All this for only 200 EUR (rated to 60m depth).
Question is: will the Nauticam solution bring something much better?
I got the Leak sentinel. The pictures you got from Vividhousing are probably from my rig.
I just love seing that little blinking green led. Knowing that my OMD is safe:). Hearing the seal pop when you open the rear door of the housing is also reasuring.
I'm going to the olympic stadium pool in Montreal (60' deep) next friday to test everything out. But so far so good.