Double Mute Design - The setting adopts bearing mute design. More flexible and quiet 360°+180° no dead Angle smooth swing way swing can be more widely used, Such as playgrounds,swings, porch swings, hammock swings, yoga, sandbag.Bearings Structure - This swing hangers takes specially designed high quality bearings which could rotate really smoothly, quiet with no squeaking.Bearings Structure.Easy Installation - Swing hangers with two 0.31" pre-drilled holes for bolting installation to wooden beams, cedar wood, rafters and/or concrete.Include 2 concrete anchor which fit concrete application and 2 hex lag bolts which fit wood application.The included drill bit is only for wood, please do not use it on concrete.Weight Limit - This swing hangers holds up to 1200lbs.For your safety,do not over it and 1200lbs may be the best.Safe and reliable.