This is the OCS made by Denkmeier that permits the bino viewer to reach focus in TeleVue refractors.
The SR OCS screws inside the diagonal, and focus can then be achieved in all 3 power arm positions. Ordinarily TeleVue refractors don't have enough focus travel to reach focus in the mid and high power arm positions. The SR OCS solves that problem.
The optic is unblemished, and has been used rarely since new one year ago.
It comes with a nicely machined aluminium housing for protection.
