Twisted needles are easy to thread and will easily pass through the holes of most smaller beads and pearls. They are very flexible and work even after they get bent. You get 25 needles in a package. They are quite inexpensive, so you can just toss them when they get too "wiggly" to use.
The "Medium" gauge needles measure 0.36mm in diameter (.014 inches); they are 9cm long (about 3.5 inches). Pkg. of 25