I had a thirty metre length to cover, and was told that it was much better to do this with one cable, which made sense. However, I had difficulty finding 30 metre length cables and, when I did, the cost was too high. So I took a risk and bought two cables, connecting them with this connector. The risk paid off. This connector is solid and the jacks from each cable fit firmly.
It does what it's supposed to, it came speedily, and it wasn't expensive. I found it very useful to get extra life out of a bass guitar speaker cab after removing the defunct integral amp head. For three quid I've in effect bought a £400 speaker cab an extra lease of life. Pleased with this product.