Super lightweight lens due polymer body (internals from brass). Revue distribution brand. Preset 5 elements design with 9 aperture blades for pleasant bokeh. Lens is clean above average (no haze, no scratches, no separation, few micro particles) and will give optimal results. Smooth focusing proper mechanics. Minor crack on plastic (just scale part of ring), see last photos, quite irrelevant. Tested Sony A7 full frame.