Ball bearing swivel have lower friction and higher working loads than non ball bearing versions. Used in conjunction with blocks and rigging systems
RONSTAN RF78 Grade Stainless Steel 316 Ball Bearing Barrel Style Eye and Eye Swivel, 1-15/16 Length, 5/16 Pin Diameter
Sailing Blocks & Pulleys, Ronstan Sailboat Hardware
500LB HD Aussie Deep Drop Corkscrew Ball Bearing Swivel
Double Ball Bearing Rescue Swivel
Ronstan Roller Furling Gear - Duckworks Boat Builders Supply
KROK Dual Rotation Ball Bearing Swivels – White Water Outfitters
Series 30 Ball Bearing Orbit™ Block, Clew Ring
Hardware - Sailboat Hardware - Page 2 - Duckworks Boat Builders Supply
Ronstan Batten Car Systems Ronstan Sailboat Hardware USA
Series 15 Ball Bearing Utility Blocks