Eye size is 9/16". Use double eyes for the hinge side of the gate, and single eyes for the pelican hook side. The eye/stud joint is threaded so the gate eye can be disassembled for threading the life line through stanchions.
Heavy on the technical side...
Hand Crimp terminals, when properly applied, are approximately 65% - 70% the strength of 7 x 7 stainless steel wire.
While this has proven adequate for use in lifelines, these fittings should not be used for standing rigging or other high load applications.
For correct attachment, manufacurer's instructions must be followed.