Compact and lightweight so that you can take it with you while on the go Safe and Comfortable: Our spacer is made of durable plastic and soft soft silicone Sealed packaging for easy unpacking and cleaning Tight air Seal around nose and mouth insuring no waste The NESSI is a spacer intended for use in the inhalation of medications which are provided by OTC MDIs. The device consists of a translucent housing a back piece and mouth piece or face mask.