Connecting links (aka couplers) such as the Crosby Lok-A-Loy are useful for more than just chain slings. You can use them anytime you need a strong, semi-permanent connection in a rigging application. Crosby revamped their connecting links to make them stronger and thus more versatile. Use the A-1337 series of Lok-A-Loy fittings with both Grade 80 and Grade 100 chain slings. Each unit is proof-test, fatigue rated and forged from alloy steel.