music on-hold

MP3 players usually have a flash storage. You can add music (https://nhac.vn/bai-hat/dap-vo-cay-dan-duong-ngoc-thai-sopYK9N) a memory card to most of the players. Minimal memory required is 128Mb (less will be enough for about a short audio book of about 6 hours). Try having the biggest memory possible belonging to the combination of flash memory and storage device. […]