wireless 4 channel USB DVR advanced digital video control function USB DVRModel:ES-601WS Features: -- wireless USB ... DVR-- 4-channel 2.4Ghz wireless video/audio-- Capture images 30 frames per second-- Record file ... rate up to 480Mpit/s,48 times-- Fluency video display,720*576 ,image up to 30 frames/s ... balance,color saturation,contrast,Gamma-- Advanced digital video control function