The "Foreigner Belt" is a belt that the Mooninites bought at the arcade using tickets they won by cheating at the game Harvest Time. According to the instruction booklet that came with the belt, the Foreigner Belt grants the wearer "all the powers of 70's super-group Foreigner". Carl recognizes this belt from Foreigner's 1983 tour with Ryan Adams, remembering fondly how he copped a feel off a drunk woman while the band was playing "wikipedia:Urgent (song) Urgent".
The belt has several powers based on songs by Foreigner, including: Freezing Carl solid (Cold as Ice), blurring Frylock's vision (Double Vision), and turning Meatwad into a rebel (Dirty White Boy). They also attempt to use songs by wikipedia:Loverboy Loverboy on Master Shake (wikipedia:Working for the Weekend Working for the Weekend, Turn Me Loose (Loverboy Song) Turn Me Loose, and wikipedia:Hot Girls in Love Hot Girls in Love) per his request, but it doesn't work because according to Ignignokt, Loverboy sucks.
After Carl thaws himself out with his tanning bed, he steals the belt from Err as the Mooninites are swimming in his pool, and dons the belt to take revenge on them. Ignignokt mocks him for not having the instruction booklet, but Carl only replies "I don't need no instructions to know how to *rock!*" He then uses the song (Hot Blooded) to heat his pool to near-boiling point, scalding the Mooninites and sending them packing in their spaceship.
Frylock then asks Carl to reverse the vision-blurring spell, but when Carl attempts to use the belt again, he ends up turning his head into a Connect Four grid because the belt was accidentally set on the song Head Games.