Quad Monitor Desk Mount: Fits 1 ultra-wide (up to 49) on top bracket and 3 standard screens (up to 27) on lower arm brackets with VESA 75x75mm or 100x100mm mounting holes. Holds up to 44 lbs on top bracket and 15.4 lbs per lower bracket Heavy-Duty Steel Construction: Clamp base (fits desktops up to 3.3 thick) and arms are made of steel for maximum strength, scratch resistance, and durability. High-capacity center-tilt joint accommodates heavier screens without sagging