A really soft but Leather . Very comfortable, you can't even fell the plastic length adjustment.
The finish of the borders is also really nice, I have used low quality straps that gets your neck and shoulders itchy after a few minutes, but I haven't have that problem with this one. and the design is wicked.
A good quality, tick leather at the end of the strap for holding the guitar. If you take care of it keeping it moist with polish or something alike, you will have a durable strap highly recommend to any one