Okay, this is probably a stupid question. I acquired a like-new ST300 in a trade. I like it a lot, but will confess that it spends most of its time in the glovebox of my truck, as it's not a light-weight. It came with two sheaths, leather and a bit larger nylon? When it is on my belt it's in the nylon. I noticed for the first time the other day that the sheath has an internal elastic band that is the width of the sheath and about 2/3rds the depth. What is it's purpose? The tool can fit under it but I don't think with the Velcro flap closure that its purpose would be additional security. thanks