The 819C-IS-2 Integrating Sphere is a 2 inch, PTFE based, 4-port integrating sphere. Its damage threshold is 5.0 J/cm². A 1 inch port plug 819M-PP-1.0 is included so that the 0° port is always plugged to the diffuse beam from opposite port. The port at 90° is used for the user selectable detector. The port at 180° is for the incoming collimated beam. The port at the North Pole location (top) is for fiber optic taping to monitor wavelength. All spheres include a baffle between the 90° and 0° ports, which prevents direct illumination from the light source to the detector port. By adding Newport's 819 Series port adapters and accessories, numerous integrating sphere configurations can be obtained. This product is replacing 819C-SL-2.