From Bitzenburger. com. 

BITZENBURGER jigs have set the industry standard for fletching tools for over 50 years. It is today's only true precision fletching instrument used by every major manufacturer of quality arrows around the world. Unparalleled quality along with simplicity, design and precision sets this fletching tool in a class by itself. Designed by experienced archers for the perfectionist who wants the finest fletcher in the world for perfect arrow making.

Features:
• Constructed of die cast alloy, this self-supporting fletching tool features a strong permanent magnet which allows for very precise and uniform placement of all feathers and vanes.
• Self-centering shaft cradle will accept and center any size available today.
• Large dials at the top and bottom of the magnet holder make it easy to adjust your angle of fletching within seconds, to fletch straight, offset or true right or left helical.
• Feather spacing of 3 fletch 120º, 4 fletch 75º x 105º, and 4 fletch 90º can be selected by a slight screw adjustment. Optional nock receivers available to achieve 60º x 120 º 4 fletch or 120 º 3 fletch cock vane down or up.
• All metal parts.
• Comes complete with wrenches and instruction sheet.
• New Nock Receivers are available for those that want to fletch Crossbow bolts.
  

Now for advice in purchasing and using a used Bitzenbuger Fletching Jig:

Brand New will run at SUGGESTED RETAIL PRICE of $79.99, so bid wisely.
Suggested Retail Price for Clamp is $39.99. A Nock Receiver-Suggested Retail is $15.95
(I do update the prices from time to time, so please keep coming back doubt that these will go down. Yet a knowledgeable bidder is a smart bidder)
Don't turn your nose up at a jig that is 30 years old or older... it is just getting broken in.

The Nock Receiver; is usualy marked with either a R, L or blank on the flat part of the Nob end of the receiver. With that make sure that the Nock receiver is proper for the clamp... meaning that, if the Clamp is for a Left wing helical, it is best that the nock receiver is marked with a "L". Same goes for a Right wing clamp, the receiver should have a "R". The same is true for a Straight clamp with a Receiver that is blank.  You can utilize the blank  nock receiver without any trouble for both Right and Left clamps.

IF using multiple clamps make sure that they are all the same far as clamps and nock receivers. 

To prevent a build up of glue on the clamp use paraffin wax to coat the clamp edge.
That way the glue will stick to the wax and not the metal of the clamp.