evh d-tuna GOLD model #: 5550121469 upc #: 832388621122 the evh d-tuna is a unique patented device that enables players to drop the e to d and back in an instant. d-tuna has been standard equipment on eddie van halen's personal guitars as well as signature series locking tremolo-equipped guitars since the early 90's. since then thousands of d-tuna's have been sold all over the world. d-tuna is proud to be endorsed by many professional players such as warren demartini (ratt) michael wilton (queensryche) and dave the snake sabo (skid row) just to name a few. bottom line...it's simple to use and it works.