By being non folding you eliminate potential source of play and rattle. The memory foam is comfortable, but not super comfy as I hoped it would be. Keeps me from losing them. However it was returned because the lights did not reliably respond to the remote control and the electronics got extremely hot to the touch. Thought these were going to be as comfortable, but they aren?t. The box said WW. my grandson is 1 1/2 and these fit perfect for the summer Most comfortable. Es un producto archiconocido y de calidad a un precio increíble, 25?. All other brands (size 5) are much bigger than these.