EPR or expiratory pressure relief (Can also be called CFlex, BIFlex) is a setting on your PAP device that helps lower the pressure on exhale. This can help make breathing out on therapy feel more comfortable. We would suggest turning on this setting if you are struggling with your pressure feeling too strong or having difficulties breathing out. This setting should be turned off if you are still snoring through your PAP mask or if you feel your pressure is not strong enough (gasping for air). If issues persist please contact our office for further suggestions.