Probably a couple of thousand feet. [All said so casually like he does this every day. On the other hand he's keeping a close eye on Jaune to make sure he doesn't suddenly bite the dust.] The boots are programmed to work in sync with the gauntlet, so when you activate them with the gauntlet they'll fire up and you'll be airborne. [And to make it easy he even labeled the button with a nice, big "ACTIVATE" sticker. There are also smaller stickers for thrust and slow so Jaune can figure out how to use the gear.]