The Pebble M350 is a wireless mouse that connects via either Bluetooth or a USB receiver. The product was originally shipped with a non-Unifying USB receiver, but it can be used by connecting to a Unifying receiver (※), and will be sold paired with a Unifying receiver. The non-Unifying USB receiver is not included. ※ https://support.logi.com/hc/ja/articles/360024552214-%E3%83%AD%E3%82%B8%E3%82%AF%E3%83%BC%E3%83%AB-Pebble-M350-%E3%82%92%E6%97%A2%E5%AD%98%E3%81%AE-Unifying-%E3%83%AC%E3%82%B7%E3%83%BC%E3%83%90%E3%83%BC%E3%81%AB%E3%83%9A%E3%82%A2%E3%83%AA%E3%83%B3%E3%82%B0%E3%81%99%E3%82%8B Connection method...Bluetooth + Unifying USB receiver #Wireless #Pebble #Silent #Slim #Unifying