I worked in an industry where knock-offs happened routinely. If you want to protect your product, you need to patent it. The patent must be filed within 12 months of the product's first public showing. Plan on a Minimum cost of $15,000 to file for a patent and there is no guarantee it will be granted. Defending a patent can run hundreds of thousands of dollars at a minimum with costs soaring into the millions.
If you have no patented technology - there is nothing to prevent someone from copying your design exactly and marketing it under a different name. (Your brand name cannot be used because that constitutes a counterfeit.)
If you want to discourage knock-offs your strategies are:
1. Continuous incremental product improvements (listen to your customers).
2. Out-of-the-box excellent quality.
3. Drive down manufacturing costs via quality control (quality at point of manufacture - not through inspection). Eliminate scrap and rework!!!!
4. Outstanding customer service. It is easier to keep your customers than it is to get new ones.
5. Constantly and clearly express your Features and Benefits so even if you are most expensive customers understand you are the best value choice.
Understand that costs to bring an exact knock-off to market are extremely high. These include molds, tools, fixtures, never-ending material sourcing and face-to-face quality control and presence at the manufacturing facility you are using. Even then if you miss something you are faced with a massive investment that will not meet your expectations and my kill your brand with the first release. If you follow the big 5 steps, your potential competitors will look for easier, less risky knock-offs.