If there is any doubt about which one to choose, then order the Universal Kit. The Universal Kit comes with a Universal Base, an R2 Lid, and an R3 Lid and will work in any M Series Humidifier.
Contact our customer service department for further assistance. 800-356-5221. The is the replacement water chamber for the Respironics M Series Humidifiers.
Images from CPAP.com have been used on this listing and may or may not accurately represent the item. Be sure to check the product description and condition information before bidding.
4.8 out of 5 by CPAP.com Customers
