This is a cable clip for the equip 19" rack cable managemant panel.

https://www.amazon.de/Equip-19-Zoll-Kabelmanagement-Panel-schwarz/dp/B000WL9DUK/ref=pd_lpo_sbs_107_img_2?_encoding=UTF8&psc=1&refRID=C96RB89ECSNANYJ6XP5Z

Kabelhalter 1: A little update for a lighter clip...