Vehicle Brake Light Flasher Module with Real-time Brake Force Monitoring. Fully Configurable. Fits Any Car or Motorcycle.

Works fine out of the box, with different flashing patterns depending on rate of deceleration. Installation requires splicing the device into CHMSL power wire (wiring diagrams for many cars available on the internet if you don't have a tester), securing the ground wire to the body of the car (like inside the trunk), and securely mounting the postage-stamp size module in the trunk, parallel to the ground. Tape works fine.Multiple aspects of module operation can be user-programmed, although that is not necessary. Download programming directions from the internet. Programming appears to be a bit tedious and non-intuitive, and requires that power be continuously supplied to the module while you are doing the programming. That means either continuously depressing the brake pedal for perhaps 15 minutes (think enlisting a friend), or connecting device to an external circuit (as shown in the website video) during programming. I was sufficiently satisfied with the default programming that I didn't mess with it.The only study that convincingly demonstrates efficacy of CHMSL was the initial San Francisco taxi cab study, which employed a contemporaneous control group. In that study, the CHMSLs all flashed, with variable rate and intensity depending on rate of deceleration. The feds dumbed it down when CHMSL became law in 1986, doing away with flashing and variable rate/intensity both in the law, and in follow-up efficacy studies which used only historical, and therefore nearly worthless, controls). It remains to be seen whether CHMSL's mandated since 1986 have any efficacy in preventing rear end collisions--but devices such as this, which largely re-create the SF taxi cab conditions, are much more likely to be effective.

I put mine under the 3rd brake light in my hatchback.I installed a 4th brake light (interior, visible through rear-view mirror) about a year ago in my car because I wanted to know when EyeSight activates the brakes during adaptive cruise control operation. Since the 4th brake light is directly wired to the 3rd brake light (parallel), the two will behave the same way, so it's easy for me to see the flasher module's behavior.I also had a switch installed next to it to disable the 4th brake light in case it became annoying at night, but it never did, so I re-purposed it by hooking it up to the two white configuration wires of the flasher module. This way, I can use it to configure it. I can also leave it in ON position to force the module to the default behavior without losing my custom setting.After much thought, following is the setting I settled on.Initial Power Up : 1-flash at rate=8. Almost no difference from normal brake behavior.Lockout disabled because I don't want it to go into lockout mode if I have to pump the brake for some reason.Medium Braking Force : 6-flashes at rate=8. I wanted to differentiate this from normal braking without standing out too much.High Braking Force : 16-flashes at rate=4. I felt that the default rate=2 was too fast.Basically, in normal conditions, I didn't want it to stand out too much, so just 1-flash and steady. On top of that, legality of the brake light modification is questionable depending on the state you live in, so I figured I'll stay out of trouble as much as possible.The contrast among the braking condition is the key in my opinion.Description of the photos:(1) Outside view. I took the photo so the 4th brake light is visible, but it isn't normally visible from the outside.(2) Inside view of the 4th brake light and the toggle switch.(3) Inside view from further away. That thing on the right is a rear-facing dashcam. Everyone should have dashcams.

When I tested this device on the kitchen table, the lights flashed upon acceleration or deceleration. I was a little surprised that acceleration in any direction would trigger it. It would seem to me that a brake light should flash only upon braking (deceleration in a particular direction). It appears that this is handled by only turning the power on while braking (see the wiring diagram). This is not quite how I waned to use it, but I thought that I could invert the logic using a relay.The first in vehicle test using the relay seemed to work, but flashed at times that was unexpected (very low lateral acceleration). I checked and re-secured my connections. The second in vehicle test resulted in a "poof" sound, a hot device and no further operation.I contacted the seller and asked for advice. I received no response.

Reliably provides initial momentary flash to high-mounted brake light on my 2005 Hyundai Santa Fe. Installation was easy as there's ample room within the brake light housing. However, the programming instructions and method could both use improvement.

For what this thing does, there's literally no excuse for not having this installed. With all the options and ease of installation and setup, the function of this thing is incredible. It works SO well! I have mine set to do a double-blink when first engaging the brake lights, and then 8 blinks during medium braking, and 16 under hard braking. The default Gforce settings are fine, I just had to change my blink patterns and speed. I also set them to blink every 4 seconds. In this world of distracting driving and heavy DC-Baltimore traffic, this thing pays for itself! (unfortunately, I was still rear-ended by a truck at a red light, since he was stopped but decided to start going even though nobody else did. lol) Highly recommended!

Easy to install, and not too difficult to custom configure. Gets the attention of other motorists!

Product as descirbed.Nice addition to my bike