This lens is to suit Pentax,
Although Used it is in very good condition and always had an expensive filter protecting the glass. It is free of scratches and fungus.
A sample photo can be found here; https://flic.kr/p/a6bqph
The Sigma 170-500mm F5-6.3 DG is a high-performance super-telephoto zoom.
This compact achromatic ultra-telephoto zoom lens covers a range up to 500mm and is ideal for photographing sport, nature and landscapes.
Lens Construction: 13 Elements in 11 Groups
Angle of View: 14.5 - 5 degrees
Number of Diaphragm Blades: 9 Blades
Minimum Aperture: F32
Minimum Focusing Distance: 300-320cm
Maximum Magnification: 1:6.6
Filter Size: 86mm
Dimensions: Diameter 92.5mm X Length 232mm
Read more at: http://www.pentaxforums.com/userreviews ... z3upBq7i6e