Linux cron: /tmp/crontab.XXXX file

I noticed some files under /tmp with the name of crontab.XXX as below:

-rw-------  1 anthony  root      949 Jul 11 09:10 crontab.XXXXS2IaZU
-rw-------  1 anthony  root      950 Jul 11 09:10 crontab.XXXXSNwiwK

What are those?

These are the temp file created when you issued the crontab -e command.

Possible single crontab being edited by 2 different session?

Anyhow, these files can be remove, just make sure you got your effective cron being stored under /var/spool/cron folder.