Are there instructions? know that sounds totally ignorant, but I'm new to diving and do not understand what the black plastic tube is for and how to attach this or the straps to the knife or my gear
SIMON C Always good to ask questions- not ignorant at all. If I remember right the knife comes with a single sheet of paper with some warranty and safety info, and a couple diagrams. The 'black plastic tube' visible next to the knife in the product image is the sheath. The knife slides and then locks into the sheath when not in use- it can be released by depressing a button. This locking mechanism helps prevent lose or accidental cuts. Generally the sheath is attached to some point on your bouncy compensator (BC,) a leg or arm etc, by running the scraps through the provided slots on the back of sheath and then around a D-ring on your BC, the inflator hose, your ankle, wrist etc. With one of these configurations, the knife is easily accessed when needed with one hand and safely put away when not in use. Hope that helps!
STEPHEN F So you can mount knife on inflater hose
TREVOR P I don't think it came with instructions, but the plastic tube is so you can attach the knife to your inflator hose. Its a very handy place to keep your knife. All you have to do is back out the screws and a plate shaped like the hose will come off. Simply put the hose into it and replace the screws. Hope this helps.
DAVID W I have used zip ties to attach knives to my gear or purchased a separate mount so I can wear it on my leg. This small of a knife would be better attached to your shoulder straps of your BC.