Parallel connectors terminate wire in limited-space applications. Similar to butt connectors, many parallel connectors feature an open-ended design with a single crimp in the center, which ensures the overlapping wires maintain optimal conductivity. Nonbutted parallel connectors can be crimped anywhere along the barrel. Both insulated and noninsulated types are ideal in applications that do not have room for additional conduit. Most insulated parallel connectors are made of vinyl, which is cost effective but provides minimal protection and has lower operating temperatures than nylon. Most noninsulated parallel connectors are made of copper. Nonbutted versions commonly feature a seamless design and tin plating for increased tensile strength and corrosion resistance.