... *Drive unit:5.25"(woofer)+(3+1.5")*2 [ tweeter] *Built-in USB and SD memory card & FM function, 2.1 ... 6.SNR:≥70DB7.separation:≥65DB8.Distortion factor:≤10% Description:1. Built-in USB and SD memory card & FM function,Support MP3 ... ³):1376sets,344ctns40'HQ (68m³):1660sets,415ctns 2.1 speaker Home Built-in USB and SD memory card & FM function,Support MP3 ...