iconwidth: Pixel width of icon; default is 56. Include "px".
Don't forget to use the {{Robelbox/close}} template after your content! This template should be used together with {{Robelbox/pad}} to pad out the box contents - see examples below, and see talk page.
This template is used or could be used on multiple language edition projects, on Beta Wikiversity. The following are the language projects that might use this template directly or indirectly. Please note that there could be other language editions that use this template but are not mentioned here.