Bi-directional Unified Transit Terminal

Isaac Sumdac invented his Bi-directional Unified Transit Terminal basically as a space bridge for the Autobots to transport between Cybertron and Earth.

It operates by putting a crack in space.

Fiction

TransTech

Professor Sumdac introduced his BUTT to Sari, Bumblebee and Optimus Prime one day, touting it as a way to get the Autobots home, and it certainly got "to the bottom of [their] transportation problem", as Optimus Prime put it. Everyone, except for possibly Sumdac himself, became aware of the acronym and spent several minutes squeezing jokes into their conversation about it. Unfortunately, it malfunctioned and transported Sari, Bumblebee, and Prime to Axiom Nexus. Bee in the City

Notes

• The BUTT is a play on the "Fully Automated Rapid Transit System" from the Animated episode "Transform and Roll Out"...which has the unintentionally puerile acronym "FARTS".