Enable Estimates Module: Allows you to create and use Estimates as part of your workflow in the application.
Last Estimate Number: Changing this will reset your Estimates numeric order to the new number that you choose.
Enable Upsell Opportunities: Allows you to add opportunities to upsell products on your invoices. Refer to this article to add upsells to products.
Do no pull inventory for Estimates: When enabled, inventory will not be reserved when added to Estimates.
Auto Expire after X days: When a value is entered, estimate will expire after the set amount of days. Leave empty to disable this feature.