Ferrules are electrical connectors used to terminate stranded wires, creating a quality, reliable connection by ensuring each wire strand conducts current when properly crimped. Especially useful when multiple reconnections could be necessary within terminal blocks or other similar devices. No breakage of wire strands when wire is bent, under stress or in a vibration environment. Twin ferrule designs allow two individual stranded conductors to be connected to the same termination, most beneficial in jumpering or other similar applications. Both styles (single and twin) offer the same features and benefits. The YF-TOOL series has been designed to crimp both the bare (type YF-UI) and insulated (type YF-I) ferrules.