Self-balancing scooters such as 'hoverboards' and monocycles are expected to be among the most popular presents this Christmas - but there are increasing concerns over safety.
As well as reports of people injured when they fall off, some have reportedly exploded while others have caught fire while charging.
Some retailers have now pulled the products from sale while further checks are made, while thousands have been seized for failing safety tests.
Here's what you need to know:
I've already bought one - what are my rights?
According to the UK's chief ombudsman Dean Dunham, customers should contact the store or online shop they bought it from to ask for written assurance that the item is safe and complies with safety rules (see below).
If they are not able to provide that reassurance, people are entitled to demand a full refund under the Consumer Rights Act.
They should also contact the Citizens Advice consumer service to report the retailer in question.
Many retailers including Amazon and Argos have already confirmed they will offer a full refund to anyone who is concerned about their product.
I haven't bought one yet, but I was going to - what should I do?
If you haven't bought one yet, you may actually find it tough to get hold of one. An number of retailers have already pulled the items from the shelves while extra safety tests are carried out.
If you find one you want to buy, make sure it meets the relevant safety standards (see below).
What should I check for?
Trading Standards teams have issued the following advice:
The plug must be a three-pin, made to BS 1363. If it doesn’t include this information, then don’t buy the product
Never leave the device charging unattended – especially overnight
A faulty cut-off switch (designed to stop the battery from continuing to charge once fully charged) could lead to the device overheating, exploding or catching fire
A plug without a fuse, as seen in many products detained so far, could also lead to a fire or explosion
Check the device and look at the shape of the plug – the first unsafe products identified often had a clover-shaped plug
The item should include the name and contact details of the manufacturer and / or importer, including an address
The device should display the genuine CE mark
Safety advice should be in English, and should advise on both charging and use
Only buy from a reputable store
What else do I need to know?
It is illegal to use self-balancing scooters such as 'hoverboards' and monocycles in public, including in parks, on roads and on footpaths.
Mr Dunham also warned that shops should be giving this information at the point of purchase.