... digital three channel ECG machine with USB BS-306A standard 12 leads 3.8" LCD screen USB interface digital three channel ... :AC.EMG FilterDrift filter:Anti-Drift SystemCMRR:≥100dB,with AC FilterInput circuit:Floating,Protection against defibrillator effectInput ... :≤15μVp-pThreshold:≤20μVPaper speed:25,50mm/s(±3%)Sensitivity:Auto,2.5,5,10,20, ... Type CF digital three channel ECG machine with USB BS-306A