# Cartridge Overview
Donations at checkout allow for the following three options:
1. **RoundUp** to the next whole monetary value
2. **Fixed amount** of merchant's choice
3. **Percentage** of the order total
The cartridge also offers an optional [Product Page Donations](/salesforce/salesforce-b2c-commerce/setup-and-configuration/site-preferences/product-page-donations.md) feature which is a micro donation made by the merchant at the product level.
How the donation amount is calculated is variable based on several configurable options. These options can be configured on the ChangeUp [dashboard](/salesforce/salesforce-b2c-commerce/setup-and-configuration/configuration-dashboard.md); functionality that is made possible by the Business Manager cartridge included in the distribution.
Once the cartridge is installed, merchants will [choose](/salesforce/salesforce-b2c-commerce/setup-and-configuration/configuration-dashboard/donate-at-checkout/charity-search.md) a default charity. This is the charity that all donations will be sent to unless other featured charities are chosen by the merchant. Several featured organizations may be selected in the configuration as well, which are displayed to the user either at checkout, or on the order confirmation page to select from.
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