What is the difference between Cobra Rods, Impel Rods and Penetreat?

The difference between Cobra rods, Impel rods, and Penetreat and is as follows:
Borate Powder

• Penetreat is a powered borate. The powder can be mixed with water and applied to bare wood. It can also be used in its powder form by drilling holes in the logs and filling them with powder or by dusting around the foundation of your home or spaces between your walls. Please see the Penetreat section for more application information.
  Crystalline Solid Borate Rods
• Impel Rods is a pure borate rod in a solid form. Please see the Impel rod section for application information.
• Cobra rod is a mixture of borate and copper hydroxide. The addition copper hydroxide in the cobra rod gives it more power to fight off wood rot (fungus) and insects. Please see the Cobra rod section for application information.
  Extra Information:
• Stay-Clean I/E is a mildewcide paint additive designed for use indoors and outdoors. It can be added to oil or latex coatings as well as wallpaper adhesive.