Universal. IPadPro202 1 is a tablet computer introduced by Apple, and its size is 1 1 inch. The iPadPro screen of 2022 also has 1 1 inch, which can be used universally. Apple iPad was designed by a team led by British-born design director Jonathan Ive. The IPad Pro202 1 12.9 inch protective case can be used, but the 2020 12.9 inch protective case cannot be used. The reason is 12.9 inch version. The height and width of the two models are the same, but the thickness of the 2 1 model is 0.5mm more. What's more, 1 1 inch speakers have different openings. 2020 speaker has 13 openings, and 202 1 speaker has 8 kinds of iPad Pro protective covers. 1. Silica gel There are two kinds of silica gel on the market, solid silica gel and liquid silica gel. Among them, solid silica gel is a common material for various DIY special-shaped protective shells in the early years. Its advantage is that it is easy to shape, but its disadvantage is that the texture is too hard and the body fit is poor. Liquid silicone is regarded as the official concept of apple with fire, and it is also the most common material for silicone shell at present. Its advantages are good hand feeling, high shock resistance and fall resistance, and its disadvantages are heavy weight and poor heat dissipation. 2. Rubber TPU is a kind of polymer compound commonly used to protect the shell, and its scientific name is thermoplastic polyurethane elastomer rubber. TPU is the main material of all kinds of transparent clear water shells on the market at present. Its advantages are higher hardness, better flexibility and higher transparency compared with silica gel, which can give consumers an impression similar to bare metal. Its disadvantage is that it is easy to deform, yellow and stick to hands after a long time, and it needs to be replaced frequently. 3. Plastics At present, the plastics commonly used to protect the shell are mainly PC and PP, among which PP is polypropylene and PC is polycarbonate, which are mainly used to make hard shells. The advantages of PC are good toughness, good transparency, lightness and high temperature resistance, but the disadvantages are that it is easy to scratch and its anti-falling ability is not so good. The advantage of PP is scratch resistance and extremely thin, but it is not resistant to high temperature and easy to deform.