With the ArduSimple Shield for second Plugin Socket you will be able to add a second High Power socket to your simpleRTK board.
If you have a simpleRTK2B Pro or simpleRTK3B you only need to plug the adapter on top of your board.
If you have a simpleRTK2B Budget, you will need to plug the adapter on top of your board and also you will need to connect 5V Out to 5V In on your simpleRTK2B Budget.
This product includes a set of headers that you will have to solder to plug the adapter.