I read this as a single code, for 25 weeks of Game Pass Ultimate. Which sounds pretty good - it's not quite 6 months, but close enough. Standard price is £11, so long as it works, this is quite the saving.
Xbox Game Pass Ultimate 25 x 7 Days Subscription Xbox One/ Windows 10
Prepare for an unprecedented experience of gaming with Xbox Game Pass Ultimate 25 x 7 days! Microsoft Ultimate 175 d. code will grant you all the benefits of Xbox Live Gold membership together with access to a collection of over 100 Xbox Game Pass games released for Xbox consoles and PC! Instead of buying each of these Xbox subscriptions separately, you have a convenient option of acquiring them all with a single Xbox Game Pass Ultimate code purchase!
Catalog of Xbox Game