Just to be on the safe side, check your states laws on flashing brake lights.
Here in the over regulated State of CA, the brake light(s) can only flash 4 times in the first 4 seconds of each brake application, then the lamp(s) must remain on. It took some searching, but I finally found a source for an electronic control module that was adjustable. So now my 3rd brake light flashes 4 times in the allotted time then goes to a steady red. I have one on both pickups and one on my car. They do get your attention. I also carry a copy of the CA Vehicle Code section (VC 25251.5(c)) in the glovebox just in case somebody wants to argue about my blinking light.
Can you post who you got it from. I like that ideal a lot better than the one that flashes all the time.