Here's my version of breakaway clips. On the primary second stage, I use a tank neck o-ring, and a light ziptie. The ziptie is weaker than the o-ring, but the o-ring gives some stretch and flexibility to the connection, so with a good pull the ziptie will break, and the second stage come free of the D-ring. The only time I really see myself having to use this is if I've clipped off the second stage to my shoulder D-ring, and get dumped by a wave or something on a shore exit/entry (and I'm usually holding the reg in my hand anyway, and I also have the necklaced secondary regulator). On the SPG, I use a much heavier ziptie, that is stronger than the o-ring, so a much harder pull is needed to break it, and the o-ring would break first instead of the ziptie. This would only ever be needed to break in the event of an entanglement, and the connection needs to be strong enough to withstand repeated clipping/unclipping of the SPG without accidently breaking and becoming an annoyance. I replaced the two small zipties on the SPG I mentioned in my earlier post before taking the picture.
On my backup lights I use cave line, as they don't need to be a breakaway connection.
