Vinyl mostly with a carbon fiber skeleton. Strong but light metal. Also equip with actuators for mobility. [He reaches up to tap his knuckles against Baymax's access port, causing the robot to tilt his head and watch what Hiro's hands are doing.] He's programmed via a few computer chips that he scans and reads and he runs off of a lithium ion battery for faster charging purposes, too. His dock's back at my brother's apartment.

[Whatever the case may be, it's obvious that Hiro knows a lot about his brother's creation and has zero problem rambling about it to a stranger who just hit him in the head. That's fine.]