The Y-Fiber Probe is suitable for reflection measurements.
Usually reflection measurements are very hard to be done preicise to achieve accurate and reproducible results as the measurement setup can change (angle etc.)
The setup is very easy. Just connect the first fiber end to the spectrometer, the second one to the light source. Then point the fiber end to the probe.
All light sources between 300nm and 1000nm can be used.
Connector type: SMA
Fiber: Solarization resistant
Fiber core diameter: 600um to spectrometer, 400um to light source