The LED lights are somewhat cumbersome powered by an external battery that can be plugged wired back to the glasses and must be stored somewhere in Klonähe. With the metal contacts you have in the long term fear that they will start to rust. The three AAA batteries ran out with me after only three months. After six weeks, the radiance of the LEDs has significantly eased by the weakening batteries.
The holder of the spectacle itself is also a bit wobbly and the whole construction slackens somewhat during folding and unfolding. One shortcoming with whom I can live, for the meetings flatter certainly also the spoiled ass. :-)