1.FLEXIBLE S DURABLEMETAL SPRING 2.STURDY DESIGN Super-stable base featuring a 400gr weightand non-slip rubber feet for maximumpertormance. 3.UNIVERSAL RUBBER CLIP Compatible with all types of cables. 4.DRAG-FREE CORD CONTROL Prevents cable snag and entanglement while moving the mouse. 5.ADJUSTABLE SPRING Unique adjustable spring allow users to select up to 9 different levels.