Back ups query

Hi,
Just got a little query that's got me puzzled.
I have recently started using Macrium Reflect the disk imaging programme in conjunction with a 32 GB memory stick to make complete back ups of my hard drive. I have noticed that although I make one image of say 12GB [which is compressed down to about 7GB] and Macrium tells me I have one image when I plug my memory stick in I get a screen image of two images.
One is about 4 GB and the other about 3 GB which goes to make the 7 GB.
They both have the same long number apart from one is 000 at the end and the other is 001. Double clicking on either takes me to the same files display which is the contents of my one and only hard drive.
Could anyone shed any light on as to why I get these two images on the stick?
When I did a restore I just selected the one image as shown by Macrium and all was well. I am just intrigued.

Regards Alex

 

It probably breaks the files into a 4GB size because that is what would be burned to a DVD. Also if the USB stick is formatted FAT32, there is a 4GB limit on the size of a file that can be transferred so this might be the reason why the file is split into 4 GB pieces.

 

Cheers Plodr, That seems to make sense.

Alex