The spring mechanism on the temple arms is fantastic.  add to this the cable ear pieces and your head will fall off before these sunglasses will.  They have a strip of foam on the forehead brace for comfort and to stop the wind.   They're excellent for bicycling, beach volleyball, hiking et.  The lenses are not super-dark and so perfect for overcast or late afternoon sporting events.   This is the only pair like them for sale here on ebay.   If you do find another pair it's unlikely that they'll have unscratched lenses.  True vintage from the 90's.