Joining the stud link chain and the anchor, a 3-link or 4-link swivel forerunner is the most common swivel-connector in use today due to its optimal design. The anchor-side of the swivel forerunner is open for fitting a ‘D’ end shackle. The other side is a common link to fit a Kenter joining shackle. The swivel forerunner is produced to ISO 1704 standards.