I was given information about this deer whistle after relating an accident I had on the Pacific Coast Highway. I'm not sure which is proper, do you hit a deer or does a deer hit you? Anyway, I had the auto store plastic deer whistles (2) on my Victory Vision while doing a 6,000 mile road trip. About 3,500 miles into the trip, just after going through Big Sur, a deer hit me. I wound up with a damaged bike and a broken Fibula. So the store bought plastic deer whistles DON'T WORK. This deer whistle from what I understand does get their attention!!! I'll buy one, just because I have had the unpleasant experience of a deer hitting me and living through it. If you like to travel back roads which are frequented by wild animals I would definitely recommend anything which can deter them. The life you save may be your own.

I've had this alert on my 1800 now for about a year and a half, and while the high-pitched sound it produces is able to be heard when stopped, it is not audible at speed. Also, I do wear a 3/4 helmet at all times. I do have a switch mounted on my right brake reservoir but often forget to turn off the unit when going through small towns because I can’t hear it with the helmet on with the engine running on my GL1800. I did mount the device in the lower vent under the running light using a very small amount of hot glue. Using hot glue, you can get a perfect 45 degree angle and using that lower vent, the device is closer to the road surface as is required. Does it work? Yes. I have yet to hit a deer and have seen deer react positively (i.e. run in a different direction than my bike) when using this unit. For pics of my installation, go to this Google Picassa link:
https://picasaweb.google.com/117522203535527215957/HornetDeerAlertSystem?authuser=0&feat=directlink

I,ve had this on my 2006 wing for a couple of years now and it definantly emitts a loud piercing noise i,m often asked does that thing really work and my reply is i,m going to have to say yes because i haven,t hit a deer yet. I only had one experience with a deer and when he saw me he looked and then ran off into the brush so i was pretty pleased with that i,ll put up with the noise for right now.Four star because of the noise

This is a must have if you ride where the deer & Antelope play. Was riding mt Davis & came upon deer in the road,they run away long before I got to them and kept running away. Great product worth every penny

I just bought my second deer alert. The first one lasted 5 years, but then stopped working. I suspect I killed it by shorting it out while cleaning up my wiring. These are definitely audible to the human ear, so you'll want to have a readily accessible on/off switch to turn it off in town or when driving at very slow speeds. This time, I used a switch cluster that mounts on top of the clutch reservoir, and I love it. Finding a good place to mount the alert can also be a challenge-- it's supposed to be mounted between 6 inches and 3 feet off the road and pointed forward at an angle of 45 degrees. I found a place to fasten it under the front cowling that just barely gives me the angle (slightly canted to the right) and misses the forks when you turn them. Mounting it inside the small opening under the right fog light is probably a better idea, but that makes it a bit trickier to wire. Oh, and the deer do seem to pay attention. My wife has been struck by a deer while driving her car, and she feels much more comfortable having the alert on when we're riding in the country.