The sight consists of a hollow tube and detachable bells at each end. You can put your own inserts in each bell then put them on the tube, so you can shoot apertures in each end, aperture in the back end and dot or crosshair in the front end, or conventional notch and post which is what I have in the sight now. The sight uses an old target style rear base with micrometer adjustments, so the adjustments are very precise and repeatable. The tube and bells keep your inserts shielded from varying light conditions.
I have not used this sight in a long time and don't have a gun to use it on anymore.
I don't know what it might be worth but I will start with a price of $100. I will ship it only to the 50 US states, with shipping included in the price.
Contact me at djwin94@hotmail.com with any questions.
The gun in the photo is not available for sale with the sight.

(I'm not sure why the photo is cutting off but you see the whole thing here:
http://i1225.photobucket.com/albums/ee3 ... _0768b.jpg
)