Hello, I have a Power XL Air Fryer oven. I noticed that the knobs on the air fryer oven does not have ridges on the knobs for grasping ergonomics. When I have to turn the knobs, it becomes very difficult, since the knobs don't have a grip. For those people with multiple disabilities and those that have increased sensory motor issues, it is many times difficult for them to grasp certain objects do the same.