Orange-lemon flavored soda. From Avery's Soda in New Britain, CT.
This is one of Avery's "gross" soda flavors, which are actually quite good. Avery's is a local soda company that fills the old Pop Shoppe niche where you buy crates of soda and bring back the bottles for refill. They also sell individual bottles through local grocers and convenience stores.
They're the only company I know of that offers orange-lemon soda, which I think is better than lemon-lime or the other supermarket brand citrus flavors.