Silver needle is a traditional type of noodle originating from Meizhou. The noodles are short, white, and semi-transparent. They're usually made from a mixture of ground rice flour (glutinous or not) and water, along with cornstarch that's often added in order to prevent breaking when cooked.
Nowadays, wheat starch is sometimes used instead of the rice flour. The rice flour and water mixture is pushed through a sieve directly into a pot of boiling water. Silver needle noodles are available in commercial versions or fresh and they're rarely made at home.