Hoverboards: They're the tech trend that no one quite knows what to make of, though everyone wants to give them a try. Of course, hoverboards don't actually hover — they're more like Segways without the handlebars.
But before you drop a few hundred bucks on one for you or an enthusiastic loved one, there are a couple things you should know.
What are these things anyway?
"Hoverboard" is the term that has come to encompass these two-wheeled, electric, semi-self-balancing scooters. You stand on them, and by pressing forward or back with one or both feet, you can cruise forward at a fast walking pace, turn corners or spin in a circle. Their weirdness — and a few well-placed celebrity endorsements — propelled the devices from virtual unknown to coveted curiosity over the course of 2015.
"We started by selling a couple a week, now we're selling a few a day," Andreas Rodriguez, of Miami Hoverboard Rental, told NBC News. "We thought our main market would be kids, but we've got teens, people in the 40s, even 50s. It's definitely a hot item for Christmas."
It's not quite at Beanie Baby or Furby levels of hype, but there should be plenty of kids hoping to unwrap a hoverboard this year.
Not all hoverboards are created equal
If you look online right now, you can find hoverboards for as little as $300 or as much as $1,500. There's a reason for that!
"A lot of people buy some from China and just put a sticker on it," said Rodriguez. "All customers see is a plastic shell and some wheels. But the quality definitely isn't there."
Among the first devices to make it to market (at least in the U.S.) were the Hovertrax and IOHawk, which happen to be the most expensive and claim to have the highest quality. Over 2015, dozens of other brands have appeared — but many are cheap knock-offs with lower-quality motors, smaller batteries or less sturdy construction. Resellers are buying these in bulk and selling them for cheap, and you get what you pay for.
"I get emails all the time where I could buy a thousand of these for a hundred bucks each," IOHawk's Kelly Morales told NBC News. "Even the cover itself and the wheels, it's just the cheapest stuff out there. On the straightaways you want to go straight, but the knockoffs kind of swerve."
Some super-cheap ones are even using batteries so bad that they're spontaneously combusting — a serious risk the London Fire Brigade felt the need to warn people about.
That said, not everyone needs the ultimate high-performance scooter — bargain models may be just fine for cruising around the house or parking lot. Just know what model you're getting and check some reviews to make sure you're not getting a hover-lemon.
Riding one may be illegal - technically
This will differ city by city and state by state, but powered transport, however small, may technically be illegal to ride on sidewalks or indoors. It depends on how local law defines them. In New York and Seattle, for instance, the devices are a class of motorized vehicle that's not legal for use on sidewalks.
But good luck finding an officer with nothing better to do than ticket you. A Seattle Police Department spokesman told NBC News he "can't recall having heard of any issues involving those." And YouTuber Casey Neistat asked a handful of NYPD officers about the legality (while riding a hoverboard), none of whom cared to trouble him about it.
Still, malls and grocery stores might not like the idea of someone motoring along the aisles, and you'll have to comply whatever the legal situation is.
These things are still very new, so expect laws, and how people react to them, to change over time — whether that means being more accepting, or being on the watch to shut them down.
Watch out for manufactured hype (and scams)
Go on Instagram, Vine, Twitter or other social media sites and you're sure to find people talking about their Swegways, Phunkeeducks and so on. But look more closely and you may find that many of these are people who received one for free from the company for promotional exposure.
"We try not to give too many away," said Morales. "But Justin Bieber was one of the guys who first found us, so obviously we gave him one. It helps create buzz."
Bieber seems to like his, but watch out for Instagram and Vine stars hocking random brands to their followers.
Of course, there's no shortage of teens showing off their new hoverboards in the streets outside their houses or chasing a cat down the hall — but their recommendations may not carry the same weight as those from Wiz Khalifa and the Bieb.
Lastly, you may have noticed the thousands of posts offering giveaways and cheap models for sale. If the price seems too good to be true, it probably is. Rodriguez warned of scams that have people wiring money to a random company in China, never to receive their product.
All this stuff is par for the course with trendy high-tech items. If you keep your eyes about you, you or your loved one should be cruising happily on a hoverboard this holiday season.