No Strings, Built-in Speaker, IN & OUT Media Ports, Volume Controls, Pre-Loaded 10 Songs, etc. Built-in Speaker, IN & OUT Media Ports, Volume Controls, Pre-Loaded 10 Songs, etc. The Air Guitar PRO is using infrared ray to replace tranditional strings.package:20*9*3 cmqty:ctn: 60 piecesG.W/N.W:14.5/16 kilos