A great feature Multistores offer is the ability to copy products between sites in the network.
To copy products from one site in the network to another, navigate to the Dashboard of the target site, the site into which you will be adding the new product. Next, select the menu Products >> Sites products. You will see a list of all the products configured in all the sites in the network, excluding products from the site you are currently editing.
To copy a product from another site in the network, simply check the box in the left column and hit the button "Copy products".
These copied products are independent, meaning changing one on the target site will not affect the one on the source site, and vice versa.