It's a strange two part clasp. Maybe it's normal for watches/jewelery, but I had trouble with it for a couple weeks. I've had it a couple months now and I'm just now getting comfortable with closing it without leverage to hold the watch in place.
And the length is not easily adjustable. I could see how the mechanism *could* be slid on the band, but it won't budge, so I assume it requires jeweler's tools if it actually moves at all.