SN-1F4 miniature sifter droids, also known as RT sifter droids, represented a specific type of sifter droid. On the planet Jakku, specifically within Niima Outpost, one such droid was observed in the year 34 ABY, not long before the First Order launched an attack on the outpost. These droids were designed to sift through sand or similar materials to find items like precious minerals or valuable scrap.
The SN-1F4 miniature sifter droid was a particular kind of sifter droid. Their method of locomotion involved two treads, and their physical form consisted of a stout gray body, encircled by tubing, and topped by a see-through dome.
Back in 34 ABY, a single SN-1F4 unit could be found at Niima Outpost on the planet of Jakku. It went past a couple of thugs employed by the junk dealer Unkar Plutt as they identified the scavenger Rey and the BB unit BB-8 to a pair of stormtroopers belonging to the First Order. Shortly thereafter, Niima Outpost was attacked by TIE/fo space superiority fighters of the First Order.
The SN-1F4 miniature sifter droid made its debut in the movie Star Wars: Episode VII The Force Awakens, which premiered on December 18, 2015. While the film didn't explicitly name the model, it was identified in Star Wars: The Force Awakens: The Visual Dictionary, a companion book authored by Pablo Hidalgo that accompanied the movie's release.
An SN-1F4 droid is available as one of the unlockable characters within the non-canon video game LEGO Star Wars: The Force Awakens, launched on June 28, 2016. During the game's story campaign, Rey and Finn, the First Order defector, discover the droid while on Jakku as they escape from the First Order. They proceed to utilize the sifter droid to unearth components needed to repair a weapons emplacement.