Probic arm

A probic arm was a device equipped to some droids, ostensibly for use as a computer jack, but commonly employed as a penetrative phallic sex toy similar to a dildo or vibrator.

Description
"And where were you hiding that?"

- Rey, to BB-8

A probic arm was a form of computer jack capable of interfacing with modular systems across the galaxy. The device consisted of a cylindrical shaft, roughly nine inches in length, covered in shiny metallic plating and tipped with a rounded cap. Probic arms were typically kept within the chassis of their droid owner, and extended for use with the activation of a subroutine. Aside from their primary function, these devices were also utilized as phallic sex toys. Some such devices had a rotation setting that allowed them to spin on their axis, providing additional pleasure to a receiving partner during penetrative sex. The metal shafts were cold.

History
While computer jacks were utilized for easy interfacing with computer systems across the galaxy, their secondary use as a sex toy afforded them a storied history in certain corners of the galaxy. Some referred to such devices as probic arms, and the phrase carried connotations that became legendary over time. Probic arms were fitted to standard astromech droids, and were sold in the flesh markets of Nuri, among many other prurient items.

New Republic Era
Leia Organa had PZ-4CO fitted with a probic arm during a diplomatic mission to the Inner Rim, visiting the flesh markets in the Shava Exurb of Urotas on Nuri and having the device installed in an unconventional location on the droid. Organa took Peazy as her lover, having heard of Naboo women enjoying the same juxtaposition, as well as rumors that Bail Organa similarly equipped his BD-3000 luxury droid.

Resistance Era
"Oh, Bee-Bee! Yes! This is what I've needed!"

- Rey, to BB-8

After the scavenger Rey discovered a scrapped Separatist aqua droid in the Vicar's junkyard on Jakku, she briefly considered fitting it with a probic arm, or a more specialized toy, to use the droid as a sexual partner.

The astromech droid BB-8 was fitted with a silver-plated probic arm capable of rotating on its axis. After encountering Rey in her shack, the droid extended his probic arm for her benefit, and even demonstrated its rotation feature to pique her curiosity. The girl decided to perform fellatio on the smooth shaft, lubricating it with her saliva, and took it vaginally while the droid rolled back and forth behind her. Rey climaxed, and BB-8 proceeded to rotate his shaft to stimulate her further. Finishing their tryst, Rey kissed his slick probe before BB-8 retracted it back into his body.

Behind the scenes
A probic arm first appeared in Legends erotica in SHAB99G - A Girl and Her Droid, and was named in Kooriv's "Mauling the Meatbag". It was introduced into erotica canon with an appearance in his 2014 erotic fiction "Rey's Awakening".