Special Features:

The s380, s370 and s371r become fiberoptic power meters when coupled with the model 260, 261 or 280 detectors; the model 260 silicon detector provides highly sensitive measurements in the 650-950 nanometer region

Properties:

Two or more different types of items, having a common mounting or mounted on each other, which together form a portion of an electrical meter, but which in itself is not a complete functioning item and cannot be assigned a more definite item name.