If there have been any difficulties with this design, it was that the temperature Management was a little off. At the best setting of 450 degrees, it only managed for getting to 432 on our oven thermometer. (The oven's inside thermometer reported it was preheated immediately after four minutes, at https://allhealthmarket.com/product/highly-recommended/appliances/air-fryers/electric-deep-fryer-without-oil-4-5l-smart-air-fryer-oven-home-toaster-rotisserie-dehydrator-led-touch-french-fries-machine/