The Sensory University Resistance Tunnel offers your child a light to medium resistance load as a simple crawl through, and a heavy load if a therapy ball is pushed through ahead of the crawl. Children in our clinic seem to flock to this exercise due to the seclusion it offers them while in the tunnel. If for some reason the child has what's known as a therapy "meltdown" while inside, the therapist or parent can roll the tunnel down in their hands and have the child out in less than 5 seconds. All tunnels are 10 Ft long, offer varying resistance as the crawl progresses, and have double secured handles on each end so the unit can be hooked to a solid structure or held by the parent or therapist on each end. Constructed of a lycra/cloth combo material. This is one of the greatest sensory integration devices ever created, and can easily be used in the home. Please do not hesitate to call if you have any questions on how this unit is used or if it will benefit your child. Colors ship random.