Industrial machine-age vintage architectural hardware... a lot of three heavy door knobs. These doorknobs are cast from either red brass or bronze and have a redder tone then the yellow brass that you usually see because the metal alloy has a higher copper content.
The pair of knobs measures about 2 1/4 inches (2.22") across and 1 3/4 inches (1.75") long to the shoulder (2" long overall). The single knob is somewhat larger and measures about 2 1/4 inches (2.28") across and 1 7/8 inches (1.878") long to the shoulder (2" long overall).
One of the pair of doorknobs has a setscrew for clamping and both of the other knobs are made with just a hole for a cross pin through the shank. These have wear and tarnish from age.