Any electronic will work as long as the bike does not have an odd ball. grote is the brand I use
http://www.grote.com/prodcat/H.html
But triton brand or what ever will work as long as it will plug into the socket.
I'll post a pic of the one on my DR later on maybe Saturday.
This is the exact one I used
http://grote.com/product.php?product_number=44810
Works like a champ and it is way tougher than anything the dealers will try and sell ya.