The Rat Tale is designed to be used with the Rat Zapper Ultra. It plugs into the top of the unit, and flashes whenever the trap has been activated. Since I had my Rat Zapper in the back of the attic, it was a big pain to go up into the attic every night to check the trap. Checking the trap a lot also discourages rats from entering it if it is constantly moved. The Rat tale has about a 12 foot long cord, and I was able to let it hang down from my attic (see picture). I kept looking up at it every time I came home, which I later found out was unnecessary since this thing flashes like crazy when it goes off. The LEDs are very bright so, there is little chance you will not notice is. I recommend it for anyone who plans to put the Rat Zapper in an inconvenient location.