TWISTER® wire connectors have earned a solid reputation as the most technically advanced wire connector available. These superior wire connectors are designed from top to bottom with features to provide more comfort and less fatigue to professional electricians. With swept wings and an expanding, live action spring, the TWISTER® supports a wide range of common wiring configurations with comfort and ease, even on the toughest combinations like solid-to-stranded. The copolymer shell expands for smooth, progressive tightening ensuring dependable connections.