The Christmas Lights, a player-deployable decorative base element, were briefly available for purchase during the Season’s Beatings! event of December 2017. They are now exclusively craftable by players who own the rather costly and rare steam item or admins that spawn them via the F1 console. There was a later reimagining of the Christmas Lights that requires electricity, the Deluxe Christmas Lights, and this light set is available every December in the item store.
The item looks and functions as a (roughly) single square frame-length strand of straight, glowing Christmas lights. This version emits light without electricity and is often used to make cheap helicopter landing pads and for lighting base interiors at night. Christmas lights may be deployed on most surfaces and are purely cosmetic.