Crowdship lets you manually assign a connection between your existing product listing variants and a specific product offered by a supplier.
First, Navigate to "My Products". Here you'll see a list of all the products that exist in your Crowdship catalog, whether they're connected to a supplier or not. Products that are not currently connected to any supplier will have "In House" as the value in the Fulfillment column.
Find the product variant you wish to connect with a supplier using the search and filter tools. You can search by SKU, UPC, title, etc.
Click the "connect" icon on the variant you want to connect to a supplier. You'll see the "Marketplace" modal open -- here you can find the corresponding supplier product to connect.
That's it! The product variant is now synced with the supplier. If you have a connected store (ex. Shopify), the your products fulfillment service, cost, sale price, inventory levels, and other attributes will automatically be updated in all connected sales channels.
You will see this products Fulfillment column status change to "Connected".
Crowdship will automatically process any orders that are created with this item moving forward.
To disconnect a product variant from it's supplier, click the 
button. Inventory updates will be disabled, and orders will no longer be processed.