Thanks, edavid, you beat me to it
So, yeah, as the specs say, 200MSa/s. That is just Nyquist-sufficient for a 100MHz sine wave in real-time acquisition. I don't imagine it'd be terribly useful for any real-life signals above 50MHz or thereabouts, as opposed to a 500MSa/s scope, which would actually be useful for 100MHz. Whether 200MSa/s are sufficient for OP's needs, I don't know, but for $200 I think there are probably better deals around.