If you're thinking of purchasing a tubular daylighting system, particularly if you are buying online, you should look for some recognition or accreditation for the product to ensure you are making the best choice.
For example, does the system have a UK accreditation, such as a BBA certificate, to confirm its required regulatory compliance and fitness for purpose? Does it have a manufacturer's backed warranty? Does the manufacturer have a long history in the daylighting industry - and do they continue to innovate? Look for recognition by building and construction professionals.
Be aware that some imported products do not meet UK regulatory requirements owing to their use of unclassified roof dome materials - specifically those with acrylic domes.