Per my previous post buried in the comments below:
Just to be clear, in case some people don't know, it is not legal to sell tritium in the US. You can purchase it from outside the US, and you can own/carry it. As a company, you cannot sell it. People selling it on Amazon are doing so illegally, and Amazon will pull the listings off occasionally once they find them. In fact, they sometimes pull our products off their site just because we use the word "tritium" in the description., which leads to a month-long effort to get them re-listed.