From the outside, the adapter looks very solid. Although the exterior is coated with gold, as are the inner contacts of copper. Anyone can see with a flashlight. The mechanism for coupling is omnipresent, therefore also known for "loose contacts" and fatigue. The supplied adapter to me was probably stored in non-optimal environment, since discoloration took place on the surface, but this was quickly eliminated with a 2000 grit sandpaper. The price seems too high for copper contacts that were not mentioned "self-evident" in the product description.
