For the dozens of you requesting a reliable prime composition without ordering several chemicals to make it, we have tested and added a mixture of ingredients that when combined with an oxidizer (not supplied) will provide a hot first fire reaction to ensure reliable ignition of the main charge. Either Potassium nitrate or Potassium perchlorate may be used with it depending on the type of composition it will be in contact with (compatibility). Add Potassium perchlorate for priming compositions containing Ammonium perchlorate (or compositions requiring higher combustion heat) and Potassium nitrate for others. Comes with instructions.