Bullet proof streamers!
Supreme Hair is probably the stalwart of synthetic fly tying materials, it has been around for a long time now, and it is still as popular as ever.
The fibers are long enough to tie the largest of flies, but it can also be cut down to lengths to suit you.
The wavey/crinkle of the fibres can be combed out with a hair drier and a brush if you require a straighter material.
Used a lot in surf candy type flies because of its strength.