Anker mentioned steel being used for the connector housing in another thread. Aluminum or steel, my concern is heat.
I bought the Powerline+ II and over time, I wished I never bought it. The heat generated on the connector housing from charging my iPhone at only up to 12W was still too warm and uncomfortable to touch.
PS: Got the Powerline III and I’m loving it! I feel a bit of warmth on the connector housing but nothing to be concerned of.