Wayfair offers 40" Waterproof Saucer Web Tree Swing 360 Rotate° Swing Set for $33.99 (orig. $40.99) with free shipping.

Product Description:
The 40-inch swing comes pre-assembled and is equipped with multiple nylon rope attachment points to hold onto for balance and stability. Support up to 440 lbs, ideal for multiple kids or even adults, the 40" large Platform allows kids to lay, stand, sit with their legs up on the platform swing, or hang over the side.