Fisher & Paykel has developed a line of high-performance circuits that has a patented spiral wire circuit technology that is unique to the industry. This technology allows for more consistent temperature delivery throughout the circuit, helping to maintain a virtually condensate-free environment and improvement for optimal humidification. 5Ft Length with Pressure Port and MDI Port. All single-heated limb circuits can be connected to either a 900MR901 or 900MR900 heated wire adapter for MR730 humidifiers and a 900MR801 or 900MR800 heated wire adapter for MR850 humidifiers. Use with Ventilator #4, #5, #6, #9, #10, #11 SEE KEY BELOW 10 Circuits per case (( KEY: #1: Bear 1®, 2®, 3®, Puritan Bennett® brand MA-1™, MA-2™. #2: Bear 1000®, Bear 5®. #3: Bird 6400® #4: Bird 8400®, T-Bird®/Legacy #5: Draeger Evita™ #6: Hamilton Veolar® #7: Infrasonics Adult Star™ #8: Newport Breeze®, Newport Wave® #9: Nellcor Puritan Bennett® 7200, 840 #10: Nellcor Puritan Bennett® 740, 760 #11: Siemens® 300/900C.))