This is a pair of New Pewter piano desk knobs which include the screws to attach them to the keyboard cover of your piano. This color of desk knobs works well on the older pianos. These knobs are designed specifically for a piano. The dimensions of each knob is 5/8" in height and 5/8" in diameter.
Please choose the type of screw needed. Either machine screws or wood screws are available. If the screw comes in from behind the fallboard, then the machine screw is what you need.