Place some thin closed cell foam padding between the glass and the holder once fitted; it will afford some shock protection. I would be surprised if anything breaks as I sometimes walk with others here using a 4x5 kit and never broken anything. You'd have to be pretty rough with the pack: falling, jumping, crashing, banging against trees, rocks etc., to bring about damage. A camera falling off a tripod head (I have seen it happen...) is an entirely different matter.