Sep 10, · "The Antec Twelve Hundred () Case is exceptional, right from the outside to the inside. It's the type of case you really want to own because there are so many excellent features. Page 1 Twelve Hundred User’s Manual Manuel de l’utilisateur Anwenderhandbuch Manuale per l’operatore Manual del usuario ; Page 2 Disclaimer This manual is intended only as a guide for Antec’s Computer Enclosures. For more comprehensive instructions on installing the motherboard and peripherals, please refer to the user’s manuals that come with those components. Save antec case to get e-mail alerts and updates on your eBay Feed. + Items in search results. Antec ANT CAS GXBLK Mid-tower Gaming Case. Brand New. Antec TwoCoolBlue LED Case Fan mm RPM 3-Pin/4-Pin Sleeve CFM. Brand New · Antec · mm · 3-Pin/4-Pin.