The Singleton bottlings are a release of Diageo intended to help introduce new customers to the world of scotch. They are designed to be approachable, drinkable, and a defining taste of a particular distillery.
The Singleton of Dufftown Sunray single malt was first produced in 2014 and part of a program to select specific barrels to produce particular flavors. The Sunray is said to use a higher proportion of "toasted bourbon casks." They describe it as smooth and intense, with an emphasis on flavor notes of black currant and baked apple." It is bottled at a relatively light 80 proof. The name comes from salmon fishing flies.