Castform Microcircuit Manufacturing Inc uses direct labor cost (DL) for its overhead rate. The production data for the month of November is as follows:

Estimated MOH costs	575,000
Estimated allocation base	?
Predetermined overhead rate	100 per DL
Actual amount of allocation base	?
Actual manufacturing overhead	610,000
Applied manufacturing overhead	590,000
Over or (under) applied overhead	?

Castform's Estimated allocation base is ______________.