This is a Cook Islands 1932 stamp. It is SG 102, the 2 1/2d Black & Blue.
The thing to note about this little beauty is that the CENTER IS INVERTED! This is a stunning error! See the SG footnotes for more information about it.
The stamp is in unmounted Mint Very Fine Condition and has its lower margin!
This item is over $100 USD so I will be shipping it using Priority Mail in the US, and Registered Mail overseas. This is to ensure that it reaches you in a safe and timely manner, and includes tracking!