GOOD / This is a USED Teleconverter, overall great shape, the glass is clean, there are no dents.
This tele converter doubles the focal length of the lens attached at the expense of two stops of light loss. The T6-2x was the earlier 2x converter, black in color, and is comprised of 6 elements in 6 groups. It is designed specifically for telephoto lenses. According to Pentax it is optimized for use at near infinity distances. It supports inner bayonet as well as outer bayonet lenses.