It means "bell seal". Something used with bathroom fixtures. We should get @driftwood to figure it out - he'd probably be willing to dismantle his bathroom just out of curiosity:-)
I'd be concerned about anything that slips over the existing evf as the rubber frame can get pullrd off pretty easy when something is attached to it, especially when the flip out screen is used alot.
…the little dutch boy with his finger up the hole? Huh? Brian. Stonebat. Really.
Well I've got a better solution than toilet humour. An old loop with a 50 cent garment elastic glued ever so scientifically to the right length to hold the little bugger in place. Even works