If you are currently using an MDI spacer, you'll want to switch over to the Pari Vortex. No other holding chamber delivers as much medication as effectively as the Vortex. Other holding chambers are made of plastic and contain a permanent electrostatic charge which attracts and holds small particles inside the chamber. The Vortex however is made of metal,so there is no static charge to interfere with your medication delivery. Includes Pari Vortex holding chamber and adult mask.