I'm sorry to be discouraging, but I am very skeptical about the possibility of selling an invention to a manufacturer. That rarely happens. The value in an invention materializes when somebody uses it to build a product and figures out how to market and sell that product and make a profit.

In very rare cases, an invention is so compelling, and its patent protection so strong, that inventors can make deals with manufacturers. That's one in a million or so. Use it to build a business, then you have value. Otherwise you're probably wasting your time and effort.