I needed a backup blade & the size was exactly what I was looking for. The blade characteristics are good for a backup knife but you DO have to heep up with rust prvention. Where the knife fails is it's locking mechanism. Unless you have this in a place that will not get bumped, which prevents putting it where you may need it, it will eventually get released of it's own accord. I dove with this knife three times, on the 2nd it came loose but I was able to catch it, on the third dive I noticed it was gone when my dive was completed. If Aeris can make a better locking mechanism, this would be a good secondary blade.