Provox Xtraflow HME 7291 Cassette Tracheostomy Breathing Aids This HME helps to make it easier to breathe. Use it during the day when you're physically active. Provox XtraFlow helps to make it easier to breathe. Use it during the day when you're physically active. If you have a voice prosthesis, simply press the HME to speak. Features: - Low breathing resistance - Reduces coughing and mucus production - Easy occlusion of the stoma for voicing - Low-profile design