Jeff was just amazed at how many different options there were to switch. Qualities of people, body parts, reality perceptions, and oh so many different options. In reality the whole Chronivac was an amazing piece of tech that he now had. Jeff's mind told him that at least while he experimented with the switch package he should probably only switch the people in his immediate family just in case he couldn't get back anything he switched quickly. Some other part in his mind told him this was irrational, because the Chronivac in general could just give him whatever he wanted or lost... but Jeff was new and a little overly cautious in some ways, and not cautious enough in others.
He looked at everyone in the Chronivac's range and saw himself... obviously a lean lanky 16 year old dude, but then the next one surprised him for a second as he saw snowball the white cat. He had assumed that this thing would only be targeting people, but snowball was a living thing and he could probably add snowball in the list of things he'd freely swap with. Then of course there was his 18 year old sister Courtney in the next room, his mom and dad in the master bedroom, his baby brother with his mom and dad, and on the first floor were his 8 year old twin younger sister's Megan and Stephanie.
Jeff started messing with the Chronivac a little bit and then came up with something he wanted to try