It is located approximately 5,000 light years away from Earth, in the Carina-Sagittarius arm.

[9] The tidal radius of the cluster is 12.1 - 15.9 parsecs (39 - 51 light years) and represents the average outer limit of NGC 4103, beyond which a star is unlikely to remain gravitationally bound to the cluster core.

[10] The cluster is not very richly populated and is dominated by moderately bright stars of 10th magnitude and fainter.

[7][12] Among the members of the cluster is AI Crucis, a short-period semi-detached massive close binary star, with orbit period 1.41771 days.

The orbital period of the binary is continuously increasing and this has been explained on the grounds of mass transfer from the less massive component to the more massive one and strong stellar wind from the hot component.