A Monitor Arm Clamp with a 3/8 Inch fitting for musical goosenecks. I use it to mount a lamp on my monitor arm. Reinforced with M5 Bolts along the fitting. The Bolt to fix the clamp in place is a M8 bolt with a nut, washers and a snap ring. Made with the measurements of these products: https://www.amazon.de/gp/product/B01MZ70QA8 https://www.thomann.de/de/gravity_ma_goose_xl.htm