They look nice, but really don't do the job - I had one on a previous car and actually had one on my current project until I found a real great deal on some rear discs with an e-brake. TSM out of Colorado sell about the best of a poor lot. The Total Performance mechanical version is really a copy the older TSM design. Their hydraulic version is illegal in many states - which Micky Lauria of TP will debate you even with a copy of the law in hand

To add to Dave S.' comments

1 - Tough to get the rotor to run true on the rough pinion yoke forging without some machine work - and then even a crap shoot. This means you have to back off the adjustment so much that it wont apply

2 - Wont hold the weight of a car on a grade as a parking brake

3 - Will NOT work as an EMERGENCY brake if your brakes were to fail for reason 2 above