These Diffuser Filters are for use with the Diffuser Elbow available for all FlexiFit 405 (HC405), FlexiFit 406 (HC406), and FlexiFit (HC407) Nasal CPAP and BiPAP masks, and all Oracle (HC451 & HC452) Oral CPAP & BiPAP Masks.
The Foam Diffuser fits in the elbow, beneath the filter cap, when in use. Each pack includes 10 Foam Diffusers. Diffusers should be changed regularly when soiled.