The product description is incorrect — these are not copper‑core connectors
These Female RCA Connectors are not gold‑plated copper contacts. I removed the galvanic gold layer, and underneath it’s the usual brass you find in low‑cost connectors. And the strain‑relief bar is magnetic.

Unfortunately, the product description is wrong. It Would be great if the description could be updated to match the actual materials.

Good quality, Easy soldering
made from metal, solid feel, screw thread works smooth and locks firmly. All in all high quality appearance. Easy to solder, soldering points for + and - are on same level and avoids uneven cable lengh cutting to keep them nicely parallel.
Diameter for cable outlet (7.5mm) is only ideal for strong cable diameters - for usual audio lines too spacey (hence 4 out of 5 stars). Make sure you use large diameter audio cable for perfect fit.