User manual (excerpt; full version available for download: click "Media" below the product image):

Instructions for Use

When applying the clips, the following regulations must be strictly observed to ensure success and absolute harmlessness. Thorough cleaning and disinfection of the stable and its continuous cleanliness are assumed. For pest control, the inner rollers of the clips are first coated with a paste made from Chamoprin powder and water. The powder can be prepared by crushing moth tablets or Chamoprin nest eggs.

Applying the clips is best done by two people. One person holds the animal on their lap in a supine position while the other person firmly holds the legs. The head of the animal should be covered with a cloth.

The screw should be well-oiled beforehand.

Now, 9 feathers of the first wing joint are placed evenly in the clip, as close to the wing bone as possible without touching it. The small covert feathers are included and gripped by the toothed leg of the clip. The screw head should be on the outer edge of the wing.

By squeezing the two legs of the clip together, the screw is first loosely tightened using a table knife or screwdriver. To prevent the feathers from sagging, the bundle of feathers is brought back to its natural position, and then the screw is tightened as tightly as possible. Both wings should be clipped. In the case of particularly strong flyers (roosters), the feathers of the second wing joint should also be clipped for several weeks if necessary.

When applied correctly, neither clips nor any disfigurements are visible on the animal. There is no need to worry about harmful effects.