This green and black mat nest swing is made from waterproof Oxford polyester fabric, which is smooth and easy to sit on. It measures 60cm across, which is the size for 1 child to swing at a time (aged 3 years and up). The inner tube is padded for softer play. If you want to have more than 1 child swing at once, a 100cm swing is better suited. The four evenly distributed suspension ropes keep the swing stable with a child on-board. You can choose to set it up as a swivelling swing or non-swivelling by hanging with either 1 tree strap or 2. Tree straps are offered as an optional accessory, though they are definitely convenient when hanging from a tree, play-set or other horizontal support. The tree straps include swivels, so if you set the swing up with 1 tree strap, it will swivel. If you want to avoid swivelling, you can use 2 tree straps - just hang them vertically or diagonally outwards to limit the swing to mainly 1 axis of motion (forward and backward).