Featuresr extension function perfect sloving phone problem of single sim card single standbyr dual sim card dual standby with phone convenient to use you do not need two phonesr support callanswer phones message privacy protection anti lost alarm etcr ready to serve in 10mr best companion for photographyr mini size with clip convenient to take alongr r noter before you use it you must download the appnotecard and connect the product with bluetoothr the product only for ios