Brand New Sealed in Factory Packaging. I have 35 available - bulk order discount. 5 or more $8.00 ea. And free shipping. Improved Gel Cushion Technology. The ComfortGel Blue continues to use a dual, gel cushion and silicone flap system. Respironics has improved the ComfortGel material. The gel is now softer and conforms to your face with greater ease. Use the separate silicone membrane that snaps on, over the gel cushion, to increase the life of the cushion and provides a unique Sure Seal Technology (SST), contouring a seal around the Gel Cushion.  System One Resistance Control. Respironics wanted a machine to achieve optimal pressure no matter which mask is used. Resistance Control is the solution, a numbering system on all of Respironics CPAP masks based on variable resistance characteristics. Each number instructs the device to compensate for different mask types. The result? A consistent and reliable pressure enhanced with all the benefits of Flex Technology no matter which mask is used.