Ruland
Ruland Beam Coupling, 13mm Outside Diameter, 5mm Bore, 19.1mm Length Coupler
Part: PCMR13-5-4-A
Miniature beam coupling handles angular and parallel shaft misalignment reliably.
Huco
Huco Beam Coupling, 13mm Outside Diameter, 4mm Bore, 19.1mm Length Coupler
Part: 721.13.1818
Tiny flexible beam coupling for precise small-bore shafts in delicate equipment.