@Amnona1
The Roku 2 model 4210, and all Roku devices that support a microSD card, only use 2 GB of a card. The devices are designed to work with that size only. Larger size cards can sometimes be properly read, but will not use over 2 GB.
Note that Roku only sells 2 GB cards for that very reason. Keep in mind that you really don't need a microSD card for a Roku to work. All they do is to increase the onboard channel/app storage. The device will not run faster, it simply won't have to re-download an app if the app is still on the card/device. If you use enough apps to cause them to roll off with the larger storage, it won't make a difference. It really depends on how many apps you use.
If you really want to use a microSD card, use the smallest you can. Anything over 2 GB is a waste.
DBDukes
Roku Community Streaming Expert
Note: I am not a Roku employee.
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