I have one just like it. Got it doing some horse trading. I would sugest saving the money for something better. Very cheaply made.I have the opportunity to purchase this rail for around $10, but I do not know who makes them, how they mount, or if they are reliable.
The person selling it claims it is new in box for Mini14/30 Ranch rifles. 7 inches long with 17 slots.
Update: Looks like it may be a China product, and it doesn't look very pretty on the rifle.