A PAP system is adapted for treatment of respiratory disease or sleep disordered breathing and includes a headgear adapted for engaging a patient's head. The PAP system also includes a patient interface adapted to be secured to and sealed against a portion of the patient's face, in use, by the headgear. The PAP system further includes a flow generator adapted to be connected to the patient interface. The flow generator is adapted to be secured by a portion of the headgear to the patient's head. In addition, the flow generator includes a blower adapted to provide pressurised breathable gas to a patient through the patient interface. The blower is at least partially vibrationally isolated from the patient's head by at least one foam layer mounted within the flow generator to secure the blower. The at least one foam layer is adapted to reduce the amount of transmitted vibration received by the patient. The flow generator also includes a mounting structure limiting a compression of the at least one foam layer due to the weight of the blower. The mounting structure includes at least one protrusion extending from an interior surface of the flow generator toward the blower.