Ribbon - customHTML - size property


How can I set the size of the container for customHTML in Ribbon?

I’m using select2 multiselect filters with the following code:
type: “block”,
direction: “col”,
items: [
{ id: “filter_1”, type: “customHTML”, html: “”},
{ id: “filter_2”, type: “customHTML”, html: “”},


You may try to define the sizes sizes right in the html of your element.