I will get back to you on that. I just found it in my desk. I myself am sighted, and have never used it for echo location - yet. Looking at it I realized that it was given out by my old employer: Blazie engineering. Coincidentally, I just ran into the founder recently. Next time I see him, I will ask him about the feedback he got on these clickers. I will say that after twenty years in a drawer it sounds good to my uneducated ears.