Korda Dark Matter Super-Heavy Tungsten Rib Tube (gravel brown) The sheer weight of this tubing will ensure that it will sink into the softer lake beds and disappear completely. It is easy to thread. Dark Matter tubing comes supplied in 2m packages. It lends itself perfectly to all manner of presentations, including lead clip and inline lead systems. This tubing sets a benchmark so if you use tubing, then you’d be mad not to check it out. Length: 2m.