Sigma 18-50mm f/2.8

Focusing distance: 20cm / 7.9in
Magnification: 0.33x
Filter size: 72mm
Lens size: ø79mm x 91.1mm / ø31.1in x 35.9in
Weight: 525g / 18.5oz
Construction: 15 elements in 13 groups
Accessories: Hood, Case

Eddie's take on it

An APS-C lens adapted for 4/3, this is a standard zoom with a "weird" focal length.

Since a much more appropriate option existed in the form of the Olympus 14-54mm, not many people bought this.

Sigma lenses of this era had various issues, from back focus, sample variation to needing to be stopped down for best results. You can expect all of these to manifest in any copy you find. If you can try before you buy, then maybe you can make it work for you.