Generally it is a bad idea to let a company probe deeply into your technical specs without having a good indicator in place that they are proposing some sort of

Generally it is a bad idea to let a company probe deeply into your technical specs without having a good indicator in place that they are proposing some sort of deal that would be favorable to you. Usually that means an LOI stating the broad terms of what they intend to do, subject only to a definitive agreement and to satisfactory due diligence. Don't be lulled that it is a big and reputable company. If they are doing their own independent development, it is relatively easy for them to claim that they developed whatever it is they later develop based solely on independent efforts and it is pretty hard for you to cut past that claim, especially when the only of doing so is to sue and spend many hundreds of thousands of dollars to try to win that suit. It should be a staged approach. The deeper they want to probe, the more they need to declare themselves. And, by the way, make sure that the NDA is very tightly drafted to severely limit the impact of potential weasel language, e.g., pertaining to independent development efforts - thus, for instance, make sure it says that such efforts must be capable of being documented by written evidence. On this point, though, it is impossible to advise in the abstract. See a good lawyer on this. Very important.