The T6615-5K is a dual-channel non-dispersive infrared (NDIR) CO2 sensor module designed for original equipment manufacturers requiring reliable gas sensing in a compact form factor. It features gold-plated optics, a dual-channel optical system with three-point calibration for enhanced stability and accuracy, and operates over a measurement range of 0 to 5000 ppm with accuracy of ±75 ppm (400–1000 ppm) or ±10% of reading (>1000 ppm). The module provides both digital output (UART @ 19200 Baud) and analog output (0–4 VDC), operates on 5 VDC regulated power with average consumption of 0.165 watts, and includes field-calibration capability for long-term accuracy maintenance. Its compact dimensions (57.15 mm × 34.67 mm × 15.24 mm) and diffusion sampling method make it ideal for HVAC systems, indoor air quality monitoring, and other applications where ABC Logic cannot be used.