This lens is a rare, excellent lens. Many members from mflenses.com highly praise this lens. Some even go further to say this is one of the best 300mm lenses around; one even claims that this lens is better than the Sigma 70-300mm APO DG.
This lens is one of the first 300mm to have a close focus function. It is able to produce a 1:3 magnification. Tamron then designed a 2X TC to mate with this lens and several others. With the TC, you're looking at a 1:1.5 magnification. Very impressive.
Here's the list of links that you can check out about this lens:
Tamron SP Adaptall-2 300mm F/5.6 Model 54B http://www.mflenses.com/tamron-sp-5.6-300-54b-lens-review-2.html
The Gallery:
Tamron SP 300mm f/5.6 54B
I'm asking
$180 + shipping + applicable fee for this lens, the TC and a K-mount PK adapter.
Sample Pictures:
If you have any question, please don't hesitate to ask me.