This little led board has a sensor in it that makes 6 red, blue and green LEDs flash and strobe when you crash or experience a bump or impact of any kind. Perfect for knowing if you actually face punched someone! 
You're probably thinking "comeon guys, if you slam into a human face you probably know it" but there's still something rewarding about the strobing lights that verify and confirm that the facepunch did indeed take place.  

Just wire it up to the battery leads on your 1S Tiny Whoop (or 5v pad) and you are good to go!