How to watch old black box videos

I pulled out an sd card to watch the black box video and checked it out, but there are only recent videos and I can't see last month's

How do I watch the last month's video?

181 4 7 years ago

pu1. When the original capacity of the black box is full, erase the oldest one first and rewrite it. So I can't see last month's

2017-12-19

pu2. What if I want to see something erased?

2017-12-19

pu3. @2 I can't check if it's erased. Or if you leave it to a data recovery company, it can be recovered, but it's not 100%

2017-12-19

pu4. I see. Thank you!

2017-12-19