If you are using these to hand a swing that hangs by 2 points, you will only need to purchase 1 set. Each box contains 2 hooks. If you are using these to hang a swing bed, or a swing that requires being hung by 4 points, you will need to purchase 2 sets. 

WARNING: This product can expose you to chemicals including nickel, which is known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov/furniture.