OnSite has the ability to integrate with SanMar's API. This feature allows users to get accurate pricing and availability of items SanMar sells. In addition, you can create and send POs directly from OnSite eliminating the need to call SanMar or use their website to order product.
Below is a link to the SanMar Size Translation Table and SanMar Shipping Methods
SanMar Integration - Setup
Using the SanMar Integration