I realized later that my choice of the word "weaker" was perhaps ill-advised. What I was thinking at the time was, Weaker per drop. If I assume eBay guy's solution is accurate, then the size of drops out of his dropper is smaller than Trapper's, so less solution is being delivered. I don't know how to evaluate any of that without an investment of $$ I'm not willing to make when I have a source right here that I trust. :)