This Water Chamber Kit for the Respironics M Series Heated Humidifier includes a universal chamber bottom and two lids for use with either of the M Series Heated Humidifiers.  

There are two versions of the Water Chamber ( R2 and R3). This kit is designed to be used with both versions.

Newly designed to correct problems that the previous generation had with water leakage between the halves of the chamber

The gasket is much larger, the plastic chamber halves are much thicker and more robust, and respironics has improved the latch mechanism