The HC385 humidifier chamber is designed for use with all Fisher & Paykel 200 Series CPAP systems including the HC200, HC201, HC220, and the HC221; as well as SleepStyle 230, 240 and 250 series systems including the HC231, HC232, HC234, HC242, HC244, and HC254. Each chamber has two ports -- one located on the side and one positioned on the top. With proper care the HC385 will generally last 3-6 months prior to needing to be replaced. The HC385 Water Chamber replaces the discontinued HC345 Water Chamber. It''s design is similar to the HC345 except with sleeker styling. Capacity 13.2 fluid ounces (400 ml). Fisher & Paykel - HC385. HCPCS Insurance Code - A7046 .