Use of colon

[xanadian]

(I am not sure whether this question belongs to CR or SC section)

Found this sentence in one of the CAT.

Advertisement: Avian Oculars are the newest in binocular technology for the professional bird watcher. For a price comparable to that of traditional binoculars, Avian Oculars are specially designed with the features demanded by birding enthusiasts: they are lightweight, compact and extremely durable. So, use Avian Oculars on your next bird watching excursion, and see some of the world’s rarest species in all of their beautiful plumage.

Is the use of colon correct in this sentence? I thought 'they are' is redundant. Can someone clarify please?

[tim]

it's totally fine. despite the fact that this is a CR question, you can look up information about correct use of the colon in our SC guide..