A Melder is a silver weapon. It has a sleek, curved handle connected to a triangle of silver with a single button located in the center. When fired from a distance, this weapon only stuns the afflicted person; at close range, and depending on where the person was shot, it can cause permanent physical damage, mental damage, and/or both.
Members of the Neverseen repeatedly threaten Sophie and her friends with Melders. These weapons were first mentioned in Keeper of the Lost Cities, where the Neverseen threatened to shoot Dex during the kidnapping scene. They were later mentioned in Exile, where both Keefe and Fitz use one. In Everblaze, Sophie and Gethen are both shot by them in the battle on Mt. Everest. Lady Gisela also used one to threaten Biana later.
Alden taught Biana how to pull someone out of the daze that a Melder could cause. When Sophie was shot, she used the method to help Sophie. The method consists of placing two fingers under the afflicted individual's temples and pressing hard. The pain is described to be excruciating.