Why is size 8/16 not accepted when syncing Impress with my eCommerce site?

Is there any limitation to what i can use in the size field. My shopify site is integrated with my ERP System, Impress. In Impress with use size 8/16 to signify ages 8 - 16. When I am trying to synch Shopify with Impress I am getting an error that the size is not accepted.

Hi, @daviddouglasbro .

Sophia here from Shopify. Welcome to the Shopify Community!

You are able to use the / character in the product size field. I tried this on my test store and successfully saved 8/16 as a size:

Can you tell me a bit more about how you’re syncing Shopify and Impress? Is there an app or CSV file involved?