Depending on your SD card size and quality settings, you will get a certain amount of recording time.
You can adjust the recording time in your camera settings, and with a higher capacity micro SD card you can also achieve longer recording times. Most cameras come with 32GB by default, but you can always check the surface of your card to see what size it is exactly.
Select your camera from below to see the possible recording times
DR900 Series
DR750S Series
DR750G Series