Copper barrel connectors are ideal for low-resistance applications. Barrel connectors facilitate electrical conductivity between separate wires. Available in a wide range of types and sizes, the majority of barrel connectors are made of copper and are designed to be used with copper conductors. One-piece copper connectors are seamless to provide optimal conductivity. Two-way copper connectors express greater pullout values than other types of connectors. Many aluminum connectors are compatible with different types of conductor cables in matching sizes. Aluminum connectors accommodate aluminum-to-aluminum and aluminum-to-copper splices.