This is a Bermuda Cover from 1886, and it was sent from Mangrove Bay to Brooklyn, New York. A 2 1/2d stamp was used as postage, but it has a full SOTN K3 #4 cancel! It also has receiver marks on the back dated 2/7/1886.
This item is over $100 USD so I will ship it using Priority Mail in the United States, and Registered Mail Overseas at buyer's expense. This is to ensure that it reaches you in a safe and timely manner, and includes tracking!