I bought this pair of connectors by mistake and never got around to using them. They are a great idea and pretty hard to get hold of in the UK. The official Neutrik description is below. I’m not a trader – check out my 100% feedback and bid with confidence. Good luck.
(2 Pack) Brand New Genuine Neutrik NA4LJX Speakon Connector Adapter Speakon to 1/4 Jack…SpeakON NL4FC – 1/4” mono jack adapterWiring: +1 to TIP and -1 to SLEEVEKeep Your 1/4′ Cables! This clever adapter lets you connect to any power amp or speaker cabinet that has a Speakon jack, without cutting off the ends of your 1/4′ cables to rewire them. Simply slip the 1/4′ end onto your speaker cable and the Speakon (4-pole) end can be plugged into the amp or cabinet. Adapts from NL4FC to 1/4 Inch 2-pole jack, wiring: +1 to TIP and -1 to SLEEVE. The new SPX-Series Speakon Adaptor NA4LJX replaces the NA4LJ. The improved design is more rugged and the rated current has been increased to 20 A.