Guarantee genuine. Not MSDN / Bulk Sale copy. Singapore retail boxset- contains product key. Selling multiple copies at cost, leftover from sale event in 2016. All BNIB sealed. Retail price S$108, selling at cost S$45. No further discount possible. Usable in two ways: (1) Extend Office 365 Personal for 12 months - including using for new installation. (2) Extend Office 365 Home for 9 months - requires an existing Office 365 Home subscription. Office 365 subscriptions are stackable up to 5 years, take advantage of this offer! Let me know if any questions - will be glad to help! Thank you!