Benefits/Features Kessler KS 561 Pressure Logic Professional Blood Pressure Monitor Digital Upper Arm Blood Pressure Monitor with Atrial Fibrillation & Irregular Heartbeat Indication & Triple Automatic Measurement Averaging Function 1 Piece Kessler Pressure Logic Professional KS 561 is an advanced, fully automatic upper arm blood pressure monitor, designed for accurate and reliable blood pressure monitoring at home or in a professional environment. It features a large illuminated LCD display for easy reading of the readings, while the oscillometric measurement technology ensures certified accuracy of ±3 mmHg. The device supports an averaging function of three consecutive measurements for greater reliability of the results and features an atrial fibrillation indicator (AFIB), an irregular heartbeat indicator (IHB) and an indicator of correct cuff application. At the same time, the classification indicator no.