inputs.text: use size card unit - first thought unit would not work micro sd card realized not card fully inserted use something small like toothpick push way used 16gb micro sd card no trouble wanted bought 64gb card amazon copied mp3 inserted not work not recognized checked formatting 16gb card fat32 formatting 64gb card xfat obviously not compatible speaker problehem fat32 formatting cannot normally used device larger 32gb mine double solution found free program ridgecrop consultants ltd go website click fat 32 formatter link left side page follow instructions use whatever size micro sd card foreseeable future used successfully drives hundreds gigs needless say 64gb micro sd card works perfectly speaker kidding speaker best ever