This is a Mauritius Rodrigues Island VERY EARLY & EXCEPTIONALLY RARE Registered Cover.  It was sent to England in 1920, with 3 6 Cent stamps and 2 registered markings on the back.

This item is over $100 USD so I will ship it using Priority Mail in the states, and Registered Mail overseas.  This is to ensure that it reaches you in a safe and timely manner, and includes tracking!