Starting tomorrow, snag a free Display Dock with your Microsoft Lumia 950 or Lumia 950 XL purchase2
Starting tomorrow, May 24th, and running to June 30th, those in the U.K purchasing the Lumia 950 or Lumia 950 XL from the Microsoft Store will receive a free Display Dock. The accessory is valued at the equivalent of $115 USD. This repeats a previous offer made last year in various regions including the U.K., Germany, U.S. and Canada.
Supplies of the free Display Dock are said to be limited, so keep that in mind. Those who purchase the Lumia 950 or Lumia 950 XL will find a pre-installed Lumia Offers app on their phone. Click on it and select 'Display Dock.' From there, enter your email address and you will receive a message including a promo code used to order the Display Dock for free. There is also a link that will take you to the page where you can order the Dock from the Microsoft Store. The promo code must be redeemed by July 30th, 2016.
source: Microsoft via WindowsCentral