I bought this case to create a portable Pi tablet and it fits perfectly. I added a 3000mah lithium polymer battery, a charge/discharge circuit, some small speakers with a small amplifier circuit and an on/off switch. It may seem like there is no more room inside after the Pi4 is installed, but if you buy small components (mostly here on Revain and Aliexpress/ebay) you can find components that will fit in and get the job done. The components I've used, including the battery, don't block any of the ports, and you can still use the Pi GPIO with an extension ribbon cable if you'd like. I get 3 hours per charge with the screen at 50% brightness and I'm very happy with the result.
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