Trimpot in MXR Micro Flanger

[dumbmonkey]

Hi all!
I have an old (1988) MXR Micro Flanger that I recently converted to true bypass.  I've had it since I was in college (20 years ago).  I love this flanger, it's really nice and subtle, of course, the enclosure has seen better days.  I was wondering if anyone knew what the trimpot inside does and if I should be checking to see if the pedal is adjusted correctly. 
Thanks in advance,
Chris