Create proper mask

[Demontager]

How can i create mask for WPA hcap file, where oclHashcat should look for
8 min digit char and not more 12 ?
So during brutforce 8 to 12 char will be tested in same time.
if am i right above only test for 10 digit chars only
?d?d?d?d?d?d?d?d?d?d

[undeath]

create a mask that covers the maximum length and then add "-i --increment-min=8" to the command line.