It's a 'Carrera' bar mfg by H&H sold by Karrousel back in the 70's - 80-'s.
You have the complete kit - for a car that lacked the frame mount and control arm ball.
Works very well, just stay away from the 'full stiff' position (2nd holes from the end) - that position will snap the drop links in a heartbeat.
Bill K
fwiw, there was a matching front one ('Carrera' by H&H) FS on a recent thread.
(also for a car that lacked any factory hardware)
http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/532758-914-911-930-anti-sway-bar-set-front-22-mm-used.html
I've had this exact set-up on my 73 since 1976 - but I do recommend getting a rear bracket welded on to replace the 'c' clamps that go around the torsion bar tube.