Karabiner

I have a keyring with a karabiner amb a dynamo lamp.

Karabiners are clip fasteners which are used extensively in rock climbing and mountaineering.[…]A karabiner’s primary task is to link the rope to protection, but they are also used to clip in to belays, to hold equipment and for abseiling.

However, looking after your gear can add years of use to rope and karabiner alike.[…]Karabiners can last 10 years or longer if they are looked after.