This direct-connect spSpO2 sensor is available for use with Criticare: 1100, 2200, 500, 500A 501, 502 series, 503, 504, 504/P, 504O/P, 504US/P, 507, 507/S, 5070/P, 507E/P/R, 507SD, 508, 509, 581, Poet (602-3A), Scholar.