A:
Well, since its a 64 GB card, about 64 gigabytes worth.
I wish I could be more specific than that since your probably wondering what that means in terms of days, hours, weeks worth of footage your recording on your camera, but honestly that's hard to say. I don't know how your camera is set to record. Is it capturing video continuously or only when it is triggered? What is the size of the file that it records to the card?
Honestly, I think 64 GB is typically enough for a few weeks with most security cameras, after your card gets full the oldest files get written over typically so you never really going to run out of space. Hope that helps.