If you're thinking of purchasing a tubular daylighting system, you need to know what you're buying is of quality. In some cases you may be purchasing the product online and haven't had a hand on experience with the product.
Some key points to look out for may well be creditions and achievements for the product. For example, if your project is required to meet building control, does the system have BBA accredition? Or maybe, has the product been recognised by or achieved any awards from a notable source? Build It Awards, Grand Designs Loves?