Fits IKEA models like Linnmon, Lagkapten, and Mittcirkel which all have a 3.4cm high desktop. Leaves a tiny bit of wiggle room which you should use to put something thin but grippy in between like a thin rubberized pad, or a small rubber band to ensure it grips in place well. Fits most common headphones like The Beyerdynamic DT 700 Pro / 900 Pro / 770 / 990 and Audio Technica ATH-M50x and a lot more.