Tokina 55mm Front Cap Plastic center snap on and 50 similar items

This lens is a good "normal" focal length (just slightly wide angle) for an APS C size sensor on a digital camera. It would be more wide on a full frame camera.

Has good sharpness and image quality for the price, though of course, it's a manual lens so you need to focus and set aperture manually on the lens.

It also focuses reasonably close and it's a somewhat "fast" lens for moderate low light compared to many zooms that only go down to F/3.5. Feels built well out of metal.

If using on a recent Pentax DSLR you may need to apply electrically conductive metallic tape to the lens in the area where the contacts on the lens mount touch since the lens isn't electrically conductive at the back. This is a weakness of the recent Pentax DSLRs that need to short these pins for aperture to work for a manual lens like this with them.

Image quality is pretty good, though maybe with a little chromatic abberation and vignetting that can be mostly corrected in software.

I've picked up a couple of other 28mm prime lenses over time and I like this Tokina better than a Vivitar 28 F/2.5 I have (though it has a warmer and creamier look and with less sharp details). I like the way a Cosina 28mm F/2.8 renders bokeh and image details in general a little more, but they're not too different.