This new defibrillator, the R-Series ALS has many advanced features such as "See-Thru CPR" technology which filters out compression artifacts on the ECG monitor, reducing your need to interrupt compressions to see underlying organized rhythms during resuscitation. Other features include built-in Pulse Oximetry, AED Mode and OneStep CPR. In addition to the defibrillator, Zoll also loaned a Symbio Rhythm Generator which connects directly to your defibrillator and external pacer for safe simulation of cardioversion and electrical capture.