This part holds glass spice jars (2.625" diameter) in place, while allowing both square and circular standard spice containers behind the glass jars. The organizer holds the jars and other containers nice and straight.

Jars can be found on Amazon https://www.amazon.com/gp/product/B000HDMKJY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1