Pentax 100mm f/2.8 WR D FA  smc Macro Lens for Pentax Digital SLR Cameras
This PENTAX macro lens features a high-grade, aluminum barrel with the high-quality, exclusive exterior design and finish unique to the PENTAX D FA series lenses.  Further, the entire mechanism of the focus ring has been reviewed and upgraded to assure flawless manual-focus operation.  For improved performance, the PENTAX D FA MACRO 100mm F2.8 WR is the first PENTAX interchangeable macro lens featuring a completely rounded diaphragm blade to create a natural, beautiful bokeh at wide apertures, while minimizing the streaking effect of point light sources. PENTAX WR lenses feature simplified weather-resistant construction to repel water and moisture.  Combined with a PENTAX weather-resistant K-7, K20D, K200D or K10D digital SLR camera body, the lens performs well in damp, inclement outdoor conditions including rain, mist, water spray and splashes.