The BIP Oscilloscope uses the sound card's input to measure signals. This means that the quality of the scope depends on the quality of your sound card. The scope has the following properties:

Sampling frequency:
The scope automatically uses the highest sample frequency available at the input that you select (usually maximal 44 kHz)

Accuracy:
The scope uses 8-bit samples to read the input signal.

Input impedance:
The same as the input impedance of your sound card.