Pollen Press are simple devices that are available in the manual or hydraulic form.
Pollen Press is mainly used to convert the kief into hash, which is basically just a heated and compressed kief. Doing so alters the chemical consistency of the material, making it more convenient to handle and consume.
The first thing to know when you're trying to use a pollen press is to have enough kief or Pollen to start with. If you use your grinder regularly, keep collecting until you have a stash of white crystals, just enough to be moulded into a solid form. Make sure that the trichomes are dry so that your hash doesn’t mould and get ruined.