The Jr. Deluxe Cheeseburger normally goes for around $1.50 (varying with location) and includes a Jr. beef patty, American cheese, crinkle-cut pickles, chopped onions, shredded lettuce, sliced tomato plus your choice of mustard, mayo, or ketchup. It's basically the Jr. version of Sonic's regular cheeseburger.
There's a limit of five Jr. Deluxe Cheeseburgers on the deal and you'll need to mention the deal when ordering. The promotion is good at participating Sonic restaurants on December 23, 2015, while supplies last.
Photo via Sonic.