I have a pair of these with the 2.5m cable adaptors. Are these better quality than the earlier headphones which I read had trouble with the headband area snapping. Not sure how old these are as I purchased them second hand. They came in the smart box.
I have two pairs of 400i’s. One with 2.5mm cables going into the ear cups and one of the new 2020 pairs with 3.5mm connectors. I’ve had the former for more than 3 years with no issues, but I’m careful with my headphones.
I consider the 3.5mm updated version to have better build quality due to the thicker and easier to solder 3.5mm connectors and the new swivel mechanism on the yokes.