An NL4 Coupler is used to link two NL4-style speaker cables together, allowing the extension of cable runs. It features NL4-compatible locking interfaces on both sides, designed to maintain a stable mechanical connection when joining cables in speaker-level audio systems. Couplers like this are commonly used in live sound, installed audio, and portable PA setups. By connecting compatible cables securely, an NL4 coupler supports flexible routing while helping keep signal paths consistent and organized.